01
Enter the round terms
Pre-money valuation and investment amount. These two numbers determine the post-money valuation and investor stake.
Startup Equity Dilution Calculator
Pre/post-money valuation, investor stake, and founder dilution — per round.
Updated Reviewed by Sajid Hussain· Editor
Try it with your numbers
Results update in real time as you type — no submit needed.
Your numbers
Results
⚡
Results appear as you type
No submit button needed
Why trust this calculator
Last updated
June 2, 2026
Coverage
9 markets · 8 currencies
Privacy
Calculated in-browser · no data stored
Pricing
Free forever · no sign-up
Understand what you're giving away
Equity dilution per round — investor stake, founder ownership, option pool
A startup equity dilution calculator shows exactly what a funding round does to everyone's ownership. Enter the pre-money valuation, investment amount, your current founder stake, and the new option pool size — and it instantly computes the post-money valuation, investor ownership, founder ownership after the round, and the dilution each party experiences. No spreadsheet, no lawyer required for the back-of-envelope check.
**Post-money valuation is the simplest calculation founders get wrong.** Post-money = pre-money + investment. A $5M pre-money with a $1M raise gives a $6M post-money. The investor owns $1M ÷ $6M = 16.7%, not $1M ÷ $5M = 20%. This distinction matters: founders who negotiate pre-money valuations but quote post-money ownership percentages are comparing apples to oranges.
**The option pool shuffle is the most common founder blind spot.** VCs use the pre-close option pool convention: the new employee equity pool is carved from your existing shares *before* the investor buys in. A 10% option pool on a $6M post-money company costs founders $600K in value and ~6.7 ownership points — but costs the investor nothing. This is why you should size the pool based on an actual 12–18 month hiring plan, not the VC's suggested 10–15%.
**Founder dilution compounds across rounds.** A typical journey — Seed (15% dilution), Series A (20%), Series B (15%) — leaves founders with roughly 57% of what they started with before accounting for option pools. This tool models one round at a time; run it sequentially for each raise to see the cumulative path.
**The valuation step-up protects founder dollar value even with dilution.** Diluting from 100% to 73% sounds bad until you notice the pre-money value of your 100% stake ($5M) is now the post-money value of your 73% stake ($4.4M) — down slightly because the option pool took more. The key insight: you are selling a percentage of a larger business. As long as the post-money valuation grows faster than the ownership percentage falls, every round increases founder paper wealth.
Quick facts
- Core output
- Pre/post-money valuation + all ownership percentages
- Option pool effect
- Pre-close convention modelled correctly
- Founder dollar value
- Pre and post paper value tracked
- High-dilution flag
- Alerts when founders drop below 50%
- Investor stake
- Investment ÷ post-money (not pre-money)
- Any currency
- Works globally — USD, GBP, EUR, INR, AUD
How it works
From round terms to a full ownership picture
Two required numbers, three ownership inputs — under a minute.
02
Enter founder ownership
Your combined founder % before the round. 100% for a first raise; lower if previous rounds have already diluted you.
03
Set the option pool
The new employee option pool size as % of post-money. This is created pre-close and dilutes founders, not the investor.
04
Read the outcome
Post-money valuation, investor stake, founder ownership after the round, dilution suffered, and paper value before and after.
Steps to use the Equity Dilution Calculator: Enter the round terms, Enter founder ownership, Set the option pool, Read the outcome.
Formula
The equity dilution formulas — standard VC term-sheet math
Based on standard VC conventions: post-money = pre-money + investment; option pool carved pre-close.
01
Post-money valuation
Post-Money = Pre-Money Valuation + Investment Amount
The company's valuation after closing the round. The investor pays the investment amount and receives the corresponding ownership percentage based on this post-money figure.
Example: $5M pre-money + $1M investment = $6M post-money.
02
Investor ownership
Investor % = Investment ÷ Post-Money Valuation × 100
What % of the company the investor buys for their capital. Uses post-money, not pre-money. Common mistake: using pre-money inflates the apparent investor stake.
Example: $1M ÷ $6M × 100 = 16.67% investor ownership.
03
Option pool dilution (pre-close convention)
Pool dilutes: founders absorb option pool % before investor comes in
VCs require the option pool to be created before close, so new shares come from existing shareholders (founders) not from the investor. A 10% post-money pool costs founders ~10% of their stake.
04
Founder ownership post-round
Founder Post % = Founder Pre % × (1 − (Investor % + New Pool %) ÷ 100)
Both the investor stake and the new option pool come out of founders' ownership. The founder retains their percentage of the remaining ownership.
Example: 100% × (1 − (16.67 + 10) ÷ 100) = 73.33% founder ownership post-round.
Worked example
Seed round: $5M pre-money, $1M raise, 10% option pool
The most common seed scenario — step by step.
Scenario
A solo founder owns 100% of their company. They raise $1M at a $5M pre-money valuation and create a 10% option pool. What happens to their ownership?
1
Step 1 · Post-money and investor stake
Post-money = $5M + $1M = $6M. Investor ownership = $1M ÷ $6M = 16.67%. The investor buys 16.67% of the company for $1M.
Post-money: $6M · Investor: 16.67%
2
Step 2 · Option pool (pre-close, dilutes founders)
The 10% option pool is created before closing — from the founder's shares. This is the "option pool shuffle": founders absorb it, not the investor.
Pool dilution: 10% of post-money = $600K founder value
3
Step 3 · Founder ownership post-round
100% × (1 − (16.67% + 10%) ÷ 100) = 100% × 73.33% = 73.33%. The founder gives up 26.67 ownership points — 16.67 to the investor and ~10 to the option pool.
Founder: 73.33% · Diluted by: 26.67%
4
Step 4 · Paper value check
Pre-money value: 100% × $5M = $5M. Post-money value: 73.33% × $6M = $4.4M. Slightly down because the option pool took proportional value. A higher pre-money would offset this.
Founder value: $5M → $4.4M
The takeaway
The founder gave up 26.67 points of ownership but raised the round. To keep founder value flat, they should have negotiated a $5.45M pre-money (so that 73.33% × $6.45M = $5M). The option pool costs $600K in paper value — negotiate it down to actual hiring needs.
Round benchmarks
Typical dilution and valuation by stage
Rough market data. Actual terms vary widely by sector, traction, and market conditions. Use as a sanity check, not a target.
| Metric | Poor | Average | Good | Excellent |
|---|---|---|---|---|
| Investor ownership (typical) | > 30% | 20–30% | 15–20% | 10–15% |
| Founder dilution per round | > 35% | 25–35% | 15–25% | < 15% |
| Option pool (new) | > 20% | 10–15% | 8–10% | Sized to plan |
| Founder ownership post-Seed | < 50% | 60–70% | 70–80% | > 80% |
Why this calculator
Calcrux vs other equity dilution calculators
Most free cap table tools show a single ownership percentage and miss the option pool pre-close effect. This one models both.
| Feature | Calcrux | Typical free tool | Spreadsheet |
|---|---|---|---|
| Pre-money vs post-money correctly | Sometimes | Manual | |
| Option pool pre-close effect | Manual | ||
| Founder dollar value (pre and post) | Manual | ||
| High-dilution flag (< 50%) | |||
| Existing option pool carried forward | Manual | ||
| Any currency | Usually USD |
Common mistakes
How equity negotiations go wrong
Calculating investor % on pre-money instead of post-money
Why it matters
Investor % = investment ÷ post-money. Using pre-money makes the investor appear to own more. A $1M investment on a $5M pre-money is 16.7% (post) not 20% (pre-money) — a meaningful difference at scale.
Fix
Always divide investment by post-money valuation. This calculator does it correctly.
Accepting a large option pool without tying it to a hiring plan
Why it matters
Every percentage point of option pool is pre-close dilution for founders. A 15% pool on a $6M post-money = $900K of founder value — for options that may never be used.
Fix
Present a 12-month hiring plan and size the pool to exactly what those hires require. Resist the VC's suggestion of an arbitrary 10–15%.
Ignoring cumulative dilution across rounds
Why it matters
Each round compounds. A founder who focuses on minimising dilution per round without modelling the cumulative effect may be surprised to hold 25% before reaching Series B.
Fix
Run this calculator sequentially for each anticipated round. Model Seed → A → B before negotiating Seed terms.
Confusing ownership % with voting control
Why it matters
Ownership percentage and voting control are separate. Dual-class share structures (e.g. Google, Facebook) give founders control even at low economic ownership. This calculator models economic ownership only.
Fix
Negotiate share class structure separately from economic ownership. This tool covers economic dilution; voting rights are a separate term sheet negotiation.
Not modelling cumulative dilution before negotiating Seed terms
Why it matters
Each round compounds. A founder who ends Seed at 73% may not realise a standard Series A takes that to ~55%, and Series B to ~42% — before accounting for option pools. Seed terms feel small; the cumulative effect is not.
Fix
Run this calculator sequentially for each anticipated round before negotiating any single round. Enter the post-Seed founder % into the next round to see the full path.
Tips
Negotiate like an informed founder
Size the option pool
Do not accept the VC's suggested pool size. Build a 12-month hiring plan, calculate the options each role gets, and present that as the justified pool size. Every % saved is founder value.
Model the post-money, not pre
Always compute investor ownership as investment ÷ post-money. This is the number that matters for dilution, not the pre-money headline.
Model all rounds first
Model Seed → A → B sequentially to see where founder ownership lands before IPO. If the path puts you below 15% at IPO, negotiate harder on early rounds.
Push the pre-money up
A higher pre-money at the same investment amount means the same dilution but higher post-money value for your retained equity. Push the valuation, not the % you keep.
Track paper value too
Dilution is only harmful if it reduces paper value. If post-money valuation grows faster than ownership % falls, every round increases your paper wealth.
Negotiate pro-rata rights early
Pro-rata rights let early investors maintain their % in future rounds. As a founder, offering pro-rata to Seed investors at Series A is often a strong signal to Seed investors — and costs you nothing unless they exercise.
Use cases
When founders use this calculator
The Equity Dilution Calculator works across every stage of the workflow.
Preparing for a seed raise
Model different pre-money valuations and investment sizes to understand the ownership tradeoff before entering term sheet negotiations.
Evaluating a VC term sheet
Plug in the term sheet numbers to immediately see post-money valuation, investor stake, and founder dilution — before calling the lawyer.
Sizing the option pool
Understand the dollar value of each % point of option pool and build a justified hiring-plan counter-proposal to the VC's suggested size.
Modeling a Series A
Enter post-Seed founder ownership to model Series A dilution and see where ownership lands before and after the round.
Explaining dilution to co-founders
Show the full ownership picture to all founders before signing, so everyone understands what they're agreeing to.
Understanding a SAFE or note conversion
Model the pre-money post-conversion to understand how a SAFE note at a valuation cap converts into equity and dilutes the table.
Glossary
Equity and dilution vocabulary
Every important term you'll encounter in this calculator and the broader topic.
- Pre-money valuation
- The company's agreed value before the investment. Post-money = pre-money + investment. This is the number founders negotiate.
- Post-money valuation
- Company value after the investment closes: pre-money + investment amount. Investor ownership = investment ÷ post-money.
- Dilution
- The reduction in an existing shareholder's ownership percentage caused by issuing new shares to investors or an option pool.
- Option pool shuffle
- The VC convention of creating the employee option pool pre-close from existing shareholders' equity (not the investor's), effectively making founders pay for the pool.
- Cap table
- Capitalisation table — the full register of who owns what percentage of the company, including all share classes, options, and warrants.
- SAFE note
- Simple Agreement for Future Equity — a convertible instrument that converts to equity at the next priced round, usually with a valuation cap and/or discount.
- Pro-rata rights
- The right for an investor to participate in future rounds to maintain their current ownership percentage. They can maintain dilution by investing their pro-rata amount.
Help & answers
Frequently asked questions
Everything you need to know about how the Equity Dilution Calculator works.
01How do you calculate equity dilution in a startup funding round?
Post-money = pre-money + investment. Investor % = investment ÷ post-money. Founder % after = founder % before × (1 − (investor% + option pool%) ÷ 100). This calculator does all three steps instantly.
02What is pre-money vs post-money valuation?
Pre-money is the company's agreed value before investment. Post-money is pre-money + investment. A $5M pre-money with $1M raised gives a $6M post-money. The investor owns $1M ÷ $6M = 16.7%, not 20%.
03What is the option pool shuffle?
The standard VC convention of creating the employee option pool pre-close — which means it comes from founders' equity, not the investor's. A 10% pool costs founders ~10 ownership points. Size it to a real hiring plan to minimise this cost.
04How much equity should a Series A investor get?
Typically 15–25% for a Series A. Below 15% and the investor may feel underexposed; above 25% and founders may struggle to raise future rounds without dropping below comfortable ownership levels.
05How does dilution compound across multiple rounds?
Each round multiplies remaining ownership. Seed: 20% dilution → 80% left. Series A: 20% more → 80% × 80% = 64%. Series B: 15% → 54%. Run this calculator for each round sequentially to model the full path.
06Does this equity calculator work for any currency?
Yes — fully global. Enter valuations in USD, GBP, EUR, INR, AUD or any other currency. All results return in the same currency. The dilution math is universal.
07SAFE vs priced round — how does equity dilution differ?
A SAFE does not create equity immediately — it converts at the next priced round, usually at a discount or valuation cap. Dilution happens at conversion, not at signing. Use this tool for priced rounds; for SAFE conversion, model the effective pre-money post-conversion.
08Does this calculator handle multiple share classes or liquidation preferences?
No — it models economic ownership only, treating all shares equally. Preferred shares carry liquidation preferences that change payouts in an exit. For a full waterfall analysis with liquidation preferences, use a dedicated cap table tool like Carta or Pulley.
Keep exploring
Related tools
Startup Burn Rate Calculator
Gross vs net burn, cash runway, and bear/bull scenarios — instantly.
Open tool
Unit Economics Calculator
LTV, CAC, LTV:CAC ratio, and CAC payback — with the 3× benchmark.
Open tool
SaaS Metrics Calculator
MRR waterfall, ARR, NRR, and Quick Ratio — the four metrics boards ask for.
Open tool
Startup Break-Even Calculator
Break-even units and revenue, contribution margin, and pricing sensitivity.
Open tool
Category
Startup & Business Intelligence
Subcategory
funding equity
Availability
Global · 9 markets
Price
Free forever
Topics
startup equity dilution calculatorequity dilution calculatorstartup valuation calculatorpre-money post-money calculatorfounder dilution calculatoroption pool dilutionSeries A dilutionseed round dilutioncap table calculatorstartup funding calculator
Explore 500+ more tools
Calculators, simulators, and decision tools for every stage of business operations.