# Calcrux

> Free calculators, simulators, and decision tools for ecommerce sellers, India businesses, manufacturers, startup founders, and financial planning. Every tool is free, requires no sign-up, runs entirely in-browser, and supports 9 currencies with automatic region detection.

## Ecommerce Seller Operations

### Financial & Profitability
- [Amazon FBA Profit Calculator](https://calcrux.com/tools/ecommerce/amazon-fba-profit-calculator): Calculate your true Amazon FBA profit, margin, and ROI in seconds.
- [Flipkart Fee Calculator](https://calcrux.com/tools/ecommerce/flipkart-fee-calculator): Your Flipkart settlement, profit, and every fee — by category, tier, and COD.
- [eBay Fee Calculator](https://calcrux.com/tools/ecommerce/ebay-fee-calculator): Real eBay profit after all six fees — and store subscription break-even.
- [Etsy Fee Calculator](https://calcrux.com/tools/ecommerce/etsy-fee-calculator): Real Etsy profit after all five fees — including the $10K Offsite Ads trap.
- [Shopify Profit Calculator](https://calcrux.com/tools/ecommerce/shopify-profit-calculator): Shopify profit after plan fee, processing and ads — and when to upgrade.
- [Selling Price Calculator](https://calcrux.com/tools/ecommerce/selling-price-calculator): Pick your channel, set your target margin — get the exact price that nets it after real marketplace fees.
- [LTV CAC Calculator](https://calcrux.com/tools/ecommerce/ltv-cac-calculator): LTV:CAC ratio, payback, and max CAC you can afford — on gross profit.
- [Discount & Promotion Profit Calculator](https://calcrux.com/tools/ecommerce/discount-profit-calculator): Before you run a discount, see the exact volume it needs and your safe floor.
- [Profit Margin Calculator](https://calcrux.com/tools/ecommerce/profit-margin-calculator): All three P&L margins stacked in one view, with markup conversion — any currency.
- [Markup Calculator](https://calcrux.com/tools/ecommerce/markup-calculator): Find your selling price, markup %, or margin from any two inputs — any currency.
- [Break-Even Point Calculator](https://calcrux.com/tools/ecommerce/break-even-point-calculator): Find exactly how many units you need to sell before every extra sale is profit.
- [Ecommerce Conversion Rate Calculator](https://calcrux.com/tools/ecommerce/ecommerce-conversion-rate-calculator): Calculate CVR, model revenue impact, and pinpoint your biggest funnel drop-off.
- [Dropshipping Profit Calculator](https://calcrux.com/tools/ecommerce/dropshipping-profit-calculator): See your real dropshipping margin after ads, fees, shipping, and returns.
- [Landed Cost Calculator](https://calcrux.com/tools/ecommerce/landed-cost-calculator): Find your true per-unit import cost after freight, duty, and fees.
- [Customer Lifetime Value Calculator](https://calcrux.com/tools/ecommerce/customer-lifetime-value-calculator): Know what a customer is really worth — margin CLV, DCF CLV, and max CAC.
- [Product Pricing Calculator](https://calcrux.com/tools/ecommerce/product-pricing-calculator): Back-solve the selling price that hits your exact target net margin after all costs.
- [Ecommerce ROI Calculator](https://calcrux.com/tools/ecommerce/ecommerce-roi-calculator): Calculate ROI, net margin, and payback period on your ecommerce investment.
- [Wholesale Pricing Calculator](https://calcrux.com/tools/ecommerce/wholesale-pricing-calculator): Set wholesale prices that protect your margin and give retailers room to sell.
- [Return Rate Calculator](https://calcrux.com/tools/ecommerce/return-rate-calculator): Calculate return rate, full return cost, and what a 1% reduction saves.
- [Amazon Referral Fee Calculator](https://calcrux.com/tools/ecommerce/amazon-referral-fee-calculator): Look up the exact Amazon referral fee for any category and selling price.
- [Amazon Storage Fee Calculator](https://calcrux.com/tools/ecommerce/amazon-storage-fee-calculator): Calculate Amazon FBA monthly and long-term storage fees by size tier and season.
- [Amazon IPI Score Calculator](https://calcrux.com/tools/ecommerce/amazon-ipi-score-calculator): Estimate your IPI score and find which factor is pulling it below 400.
- [Contribution Margin Calculator](https://calcrux.com/tools/ecommerce/contribution-margin-calculator): Calculate contribution margin per unit, CM ratio, and break-even point.
- [Product Profitability Calculator](https://calcrux.com/tools/ecommerce/product-profitability-calculator): Per-unit profit, margin, ROI, and monthly projections — fees and ads included.
- [Ecommerce Unit Economics Calculator](https://calcrux.com/tools/ecommerce/ecommerce-unit-economics-calculator): Contribution margin, break-even units, and monthly P&L from variable costs.
- [Revenue Projection Calculator](https://calcrux.com/tools/ecommerce/revenue-projection-calculator): Project 3–24 months of revenue from run rate, growth rate, and seasonality.

### Inventory & Operations
- [Amazon FBA Restock Calculator](https://calcrux.com/tools/ecommerce/amazon-fba-restock-calculator): Reorder point, days to reorder, and order quantity — no spreadsheets needed.
- [GMROI Calculator](https://calcrux.com/tools/ecommerce/gmroi-calculator): Your GMROI, the ~3.2 retail benchmark verdict, and both levers that move it.
- [Economic Order Quantity (EOQ) Calculator](https://calcrux.com/tools/ecommerce/eoq-calculator): The EOQ calculator with orders/year, cycle days, and bulk discount check.
- [Inventory Turnover Calculator](https://calcrux.com/tools/ecommerce/inventory-turnover-calculator): Inventory turnover, DSI, and supply weeks — with a benchmark verdict.
- [Inventory Forecast Calculator](https://calcrux.com/tools/ecommerce/inventory-forecast-calculator): Project demand for 30–90 days with growth trend and seasonal adjustment.
- [Reorder Point Calculator](https://calcrux.com/tools/ecommerce/reorder-point-calculator): Calculate the exact inventory level to trigger your next order — no stockouts.
- [Inventory Carrying Cost Calculator](https://calcrux.com/tools/ecommerce/inventory-carrying-cost-calculator): Calculate the true annual cost of holding inventory — all cost components.
- [Stock Coverage Calculator](https://calcrux.com/tools/ecommerce/stock-coverage-calculator): See how many days your stock will last and whether a stockout is coming.
- [Dead Stock Calculator](https://calcrux.com/tools/ecommerce/dead-stock-calculator): Quantify dead stock costs and decide: liquidate, discount, or hold.

### Shipping & Logistics
- [Dimensional Weight Calculator](https://calcrux.com/tools/ecommerce/dimensional-weight-calculator): Dimensional, billable, and chargeable weight — all carriers, lb or kg.
- [Walmart Fee Calculator](https://calcrux.com/tools/ecommerce/walmart-fee-calculator): Real Walmart profit after referral fee, WFS, and $0 monthly fees.

### Ads & Marketing
- [Amazon Ads ROAS Calculator](https://calcrux.com/tools/ecommerce/amazon-ads-roas-calculator): True Amazon ad ROAS, break-even, and the max CPC you can profitably bid.
- [Amazon PPC Break-Even Calculator](https://calcrux.com/tools/ecommerce/amazon-ppc-break-even-calculator): Break-even ACoS, max CPC, and min CVR — from your product economics.
- [Average Order Value Calculator](https://calcrux.com/tools/ecommerce/average-order-value-calculator): Calculate your AOV, get a free-shipping floor, and model what a lift is worth.
- [Break-Even ROAS Calculator](https://calcrux.com/tools/ecommerce/break-even-roas-calculator): Minimum profitable ROAS for any channel — break-even, target, and ACoS.
- [Cart Abandonment Calculator](https://calcrux.com/tools/ecommerce/cart-abandonment-calculator): Cart abandonment rate, lost revenue, and how much you can realistically recover.
- [Amazon ACOS Calculator](https://calcrux.com/tools/ecommerce/amazon-acos-calculator): Calculate Amazon ACOS, break-even ACOS, and net profit from your ad campaigns.
- [Amazon TACoS Calculator](https://calcrux.com/tools/ecommerce/amazon-tacos-calculator): Calculate Amazon TACoS and see if ads build organic rank or just buy clicks.
- [Cost Per Acquisition (CPA) Calculator](https://calcrux.com/tools/ecommerce/cost-per-acquisition-calculator): Calculate CPA, break-even threshold, and whether each acquisition is profitable.
- [Marketing ROI Calculator](https://calcrux.com/tools/ecommerce/marketing-roi-calculator): Measure marketing ROI from gross profit to LTV-adjusted return on spend.
- [Marketing Efficiency Ratio (MER) Calculator](https://calcrux.com/tools/ecommerce/marketing-efficiency-ratio-calculator): Measure blended MER across all channels — the true sign of marketing health.
- [Customer Payback Period Calculator](https://calcrux.com/tools/ecommerce/customer-payback-period-calculator): Find out how many months to recover your CAC — the metric that limits scale.
- [Customer Retention Rate Calculator](https://calcrux.com/tools/ecommerce/customer-retention-rate-calculator): Retention rate, churn rate, and the revenue value of keeping one more customer.
- [Ad Spend Scaling Simulator](https://calcrux.com/tools/ecommerce/ad-spend-scaling-simulator): Simulate profit, ROAS, and marginal return of scaling your ad budget.

## India Business Operations

### Salary & Take-Home
- [In-Hand Salary Calculator](https://calcrux.com/tools/india-business/in-hand-salary-calculator): Convert CTC to monthly take-home with full tax and deduction breakdown.
- [HRA Calculator](https://calcrux.com/tools/india-business/hra-calculator): Exact HRA exemption with a full 3-rule breakdown — free for FY 2025-26.
- [Salary Breakup Calculator](https://calcrux.com/tools/india-business/salary-breakup-calculator): Split your CTC into Basic, HRA, PF, gratuity and take-home.
- [Salary Hike Calculator](https://calcrux.com/tools/india-business/salary-hike-calculator): Find your hike percentage or new salary after a raise.
- [Leave Encashment Calculator](https://calcrux.com/tools/india-business/leave-encashment-calculator): Value your unused leave and its tax-free part.
- [Statutory Bonus Calculator](https://calcrux.com/tools/india-business/statutory-bonus-calculator): Work out your statutory bonus under the Payment of Bonus Act.

### Income Tax & TDS
- [Income Tax Calculator India](https://calcrux.com/tools/india-business/income-tax-calculator): Your total income tax for the year — old vs new regime compared, FY 2025-26.
- [TDS Calculator](https://calcrux.com/tools/india-business/tds-calculator): Tax deducted at source on a payment — the right rate and amount by section.
- [Advance Tax Calculator](https://calcrux.com/tools/india-business/advance-tax-calculator): Pay your income tax in instalments through the year — amounts and due dates.
- [Professional Tax Calculator](https://calcrux.com/tools/india-business/professional-tax-calculator): The state tax on your payslip — PT by state, separate from income tax.
- [Capital Gains Tax Calculator](https://calcrux.com/tools/india-business/capital-gains-tax-calculator): Work out STCG and LTCG tax on shares, property and gold.
- [80C Calculator](https://calcrux.com/tools/india-business/section-80c-calculator): Add up your 80C investments and the tax you save.
- [Home Loan Tax Benefit Calculator](https://calcrux.com/tools/india-business/home-loan-tax-benefit-calculator): See the tax you save on your home loan interest and principal.
- [80D Calculator](https://calcrux.com/tools/india-business/section-80d-calculator): Find your health-insurance tax deduction for family and parents.
- [80E Calculator](https://calcrux.com/tools/india-business/section-80e-calculator): Find the tax you save on your education loan interest.
- [80G Calculator](https://calcrux.com/tools/india-business/section-80g-calculator): Find your tax deduction on donations to charities and funds.
- [80TTA & 80TTB Calculator](https://calcrux.com/tools/india-business/section-80tta-80ttb-calculator): Tax-free deduction on your savings and deposit interest.
- [TDS on Salary Calculator](https://calcrux.com/tools/india-business/tds-on-salary-calculator): See the monthly TDS your employer cuts from your salary.

### Retirement & Savings
- [EPF Calculator](https://calcrux.com/tools/india-business/epf-calculator): Project your EPF corpus, interest earned, and EPS pension at retirement.
- [Gratuity Calculator](https://calcrux.com/tools/india-business/gratuity-calculator): Calculate gratuity under the Payment of Gratuity Act — and your tax-free amount.
- [NPS Calculator](https://calcrux.com/tools/india-business/nps-calculator): Project your NPS corpus, tax-free lump sum and monthly pension at 60 — free.
- [PPF Calculator](https://calcrux.com/tools/india-business/ppf-calculator): Project your PPF maturity and tax-free interest — yearly or monthly deposits.
- [PPF Goal Calculator](https://calcrux.com/tools/india-business/ppf-goal-calculator): Work backwards from your PPF goal to the exact yearly deposit you need.
- [Sukanya Samriddhi Yojana Calculator](https://calcrux.com/tools/india-business/sukanya-samriddhi-yojana-calculator): Project your Sukanya Samriddhi (SSY) maturity at 21 — tax-free at 8.2%.
- [FD Calculator](https://calcrux.com/tools/india-business/fd-calculator): See your fixed deposit maturity, interest and TDS — quarterly compounding.
- [RD Calculator](https://calcrux.com/tools/india-business/rd-calculator): See your recurring deposit maturity and interest — and the TDS on it.
- [NSC Calculator](https://calcrux.com/tools/india-business/nsc-calculator): See your NSC maturity and interest at 7.7% — the 5-year certificate.
- [SCSS Calculator](https://calcrux.com/tools/india-business/scss-calculator): See your Senior Citizen Savings Scheme quarterly income at 8.2%.
- [Post Office MIS Calculator](https://calcrux.com/tools/india-business/post-office-mis-calculator): See your monthly income from the Post Office MIS at 7.4%.
- [KVP Calculator](https://calcrux.com/tools/india-business/kvp-calculator): See how fast Kisan Vikas Patra doubles your money at 7.5%.
- [APY Calculator](https://calcrux.com/tools/india-business/apy-calculator): Find your Atal Pension Yojana monthly contribution by age.

### Loans & EMI
- [EMI Calculator](https://calcrux.com/tools/india-business/emi-calculator): Find your monthly EMI, total interest and full repayment breakdown.
- [Loan Prepayment Calculator](https://calcrux.com/tools/india-business/loan-prepayment-calculator): See the interest you save and how much sooner you finish.
- [Loan Eligibility Calculator](https://calcrux.com/tools/india-business/loan-eligibility-calculator): See how much loan you qualify for on your income (FOIR).
- [Loan Balance Transfer Calculator](https://calcrux.com/tools/india-business/loan-balance-transfer-calculator): See the interest you save by switching to a lower rate.

### Freelancers & GST
- [Freelancer Tax Calculator](https://calcrux.com/tools/india-business/freelancer-tax-calculator): Section 44ADA tax, advance tax, GST estimate and audit check — free.
- [GST Calculator](https://calcrux.com/tools/india-business/gst-calculator): Add or remove GST and split CGST, SGST & IGST — with current GST 2.0 rates.
- [GST Late Fee & Interest Calculator](https://calcrux.com/tools/india-business/gst-late-fee-calculator): Work out the GST late fee and 18% interest on a late return.

## Manufacturing & ERP Operations

### Production Planning
- [OEE Calculator](https://calcrux.com/tools/manufacturing/oee-calculator): Availability, performance, quality, and the Six Big Losses — in one view.
- [Takt Time Calculator](https://calcrux.com/tools/manufacturing/takt-time-calculator): Set your production pace: takt time, required output rate, and line status.
- [Production Capacity Calculator](https://calcrux.com/tools/manufacturing/production-capacity-calculator): Theoretical, effective, and net capacity — for machines, shifts, and efficiency.

### Maintenance & Reliability
- [MTBF & MTTR Calculator](https://calcrux.com/tools/manufacturing/mtbf-mttr-calculator): Mean time between failures, mean time to repair, and machine availability.

### Inventory & Procurement
- [Safety Stock Calculator](https://calcrux.com/tools/manufacturing/safety-stock-calculator): Safety stock, reorder point, and holding cost for any service level target.

## Startup & Business Intelligence

### Startup Finance
- [Startup Burn Rate Calculator](https://calcrux.com/tools/startup/startup-burn-rate-calculator): Gross vs net burn, cash runway, and bear/bull scenarios — instantly.
- [Startup Break-Even Calculator](https://calcrux.com/tools/startup/startup-break-even-calculator): Break-even units and revenue, contribution margin, and pricing sensitivity.

### Funding & Equity
- [Equity Dilution Calculator](https://calcrux.com/tools/startup/startup-equity-dilution-calculator): Pre/post-money valuation, investor stake, and founder dilution — per round.

### Strategic Planning
- [Unit Economics Calculator](https://calcrux.com/tools/startup/startup-unit-economics-calculator): LTV, CAC, LTV:CAC ratio, and CAC payback — with the 3× benchmark.
- [SaaS Metrics Calculator](https://calcrux.com/tools/startup/saas-metrics-calculator): MRR waterfall, ARR, NRR, and Quick Ratio — the four metrics boards ask for.

## Operational Financial Planning

- [SIP Calculator](https://calcrux.com/tools/financial/sip-calculator): Project your SIP maturity, total returns, and real worth after inflation — free.
- [Lumpsum Calculator](https://calcrux.com/tools/financial/lumpsum-calculator): What a lumpsum investment grows into — total value, real worth, year by year.
- [Compound Interest Calculator](https://calcrux.com/tools/financial/compound-interest-calculator): Compound interest on a balance and deposits — final balance, APY and real worth.
- [SIP vs Lumpsum Calculator](https://calcrux.com/tools/financial/sip-vs-lumpsum-calculator): Compare SIP vs lumpsum on the same sum — verdict, gap, and when each wins.
- [SIP Goal Calculator](https://calcrux.com/tools/financial/sip-goal-calculator): Work backwards from your goal to find the exact monthly SIP you need.
- [Retirement Calculator](https://calcrux.com/tools/financial/retirement-calculator): Find the corpus you need and the monthly SIP to get there.
- [FIRE Calculator](https://calcrux.com/tools/financial/fire-calculator): Your FIRE number, the earliest age you can retire early, and whether the corpus survives — free.

## Guides
- [Amazon FBA Fees Explained (2026)](https://calcrux.com/guides/amazon-fba-fees): Every FBA cost — referral, fulfillment, storage and the new 2024–26 fees — with a worked example.
- [Amazon Referral Fees by Category](https://calcrux.com/guides/amazon-referral-fees): The commission Amazon takes per sale by category, plus the tiered and $0.30-minimum rules.
- [Amazon FBA Fulfillment Fees & Size Tiers](https://calcrux.com/guides/amazon-fba-fulfillment-fees): The flat per-unit pick-pack-ship fee and how size tiers and weight set it.
- [Amazon FBA Storage Fees & Aged Inventory](https://calcrux.com/guides/amazon-fba-storage-fees): Per-cubic-foot monthly storage, the Q4 rate spike, and the 181-day aged-inventory surcharge.

## Key Pages

- [All Tools Directory](https://calcrux.com/tools): Browse and search all 105 free calculators by category.
- [Ecommerce Seller Operations Tools](https://calcrux.com/tools/ecommerce): Profit, inventory, shipping, and ads tools for marketplace sellers
- [India Business Operations Tools](https://calcrux.com/tools/india-business): HR, salary, GST, and business finance tools for Indian businesses
- [Manufacturing & ERP Operations Tools](https://calcrux.com/tools/manufacturing): Production planning, costing, and maintenance tools for manufacturers
- [Startup & Business Intelligence Tools](https://calcrux.com/tools/startup): Runway, fundraising, equity, and growth tools for founders
- [Operational Financial Planning Tools](https://calcrux.com/tools/financial): Personal finance, business planning, and risk analysis tools
- [About Calcrux](https://calcrux.com/about): Mission, approach, and platform overview.
- [Privacy Policy](https://calcrux.com/privacy): All calculations run in-browser — no data stored or transmitted.