Free Equity Dilution Calculator — See How Much Equity You Keep After Raising

June 11, 2026 • 7 min read

Every time you raise a funding round, you give up a piece of your company. But how much exactly? And more importantly — what will you own after your Seed, Series A, and Series B?

A free equity dilution calculator gives you instant answers. No signup, no credit card, no complicated cap table software. Just enter your numbers and see your ownership trajectory in seconds.

Try the Free Equity Dilution Calculator →

Enter your startup details. See your ownership after every funding round. No signup required.

What Is Equity Dilution?

Equity dilution happens when a company issues new shares, reducing the ownership percentage of existing shareholders. For founders, this typically occurs during:

• Funding rounds — Investors buy equity, adding new shareholders
• Option pool creation — Shares reserved for employees dilute existing owners
• Convertible note conversion — SAFEs and notes convert to equity at a discount
• Cofounder splits — Adding team members means dividing the pie

Here's the math: if you own 50% of your company and raise a round where investors take 20%, your new ownership is 50% × (1 - 0.20) = 40%. But it's rarely that simple — investors often require an option pool expansion that dilutes you further.

Why You Need a Dilution Calculator

Most founders have a vague sense of dilution but can't model it precisely. A dilution calculator helps you:

1. Negotiate term sheets — Know the exact cost of investor terms before you sign
2. Plan future rounds — Project ownership through Seed, Series A, B, and beyond
3. Evaluate exit scenarios — See what your stake is worth at different exit valuations
4. Compare with benchmarks — Check if your dilution is normal for your stage
5. Communicate with cofounders — Get everyone aligned on equity expectations

How the Free Dilution Calculator Works

The FounderMath equity dilution calculator uses real VC math — the same formulas investors use to calculate ownership after funding rounds. Here's what you enter:

• Your current equity percentage — What you own right now
• Number of cofounders — Affects how the pie is already divided
• Current funding stage — Pre-seed, Seed, Series A, or Series B
• Planned future rounds — How many more rounds you expect to raise
• Current valuation — Your company's current worth
• Exit goal — The valuation you're aiming for at exit

In return, you get:

• Round-by-round dilution table — Your ownership after each round
• Key metrics — Starting equity, post-raise equity, final ownership, exit value
• Industry benchmark comparison — How your dilution compares to averages
• Visual dilution chart — Your ownership curve over time (in the full report)
• Personalized recommendations — Specific actions to protect your equity

A Real Example

Let's walk through a realistic scenario. You're a solo founder with 100% of your company, currently at Seed stage, planning to raise 2 more rounds:

That's 66.9% total dilution over two rounds. Your $100M exit pays you $33.1M. But what if you negotiate harder and reduce dilution by just 3% per round?

Free vs. Paid: What You Get

The free equity dilution calculator gives you a comprehensive preview of your ownership trajectory — no signup needed. For founders who want the full picture, the premium report includes:

Or unlock the full report for free by entering your email — we'll send you weekly equity insights along with your complete analysis.

Other Free Equity Calculators

FounderMath offers a complete suite of free equity calculators for startup founders:

When to Use a Dilution Calculator

The best time to model your dilution is before you start fundraising. But here are key moments when a dilution calculator is essential:

• Before signing a term sheet — Model the exact impact of investor terms
• When comparing multiple term sheets — See side-by-side dilution scenarios
• Before creating an option pool — Understand the full dilution cost of hiring
• When planning your fundraising timeline — Model 2, 3, or 4 rounds ahead
• Before a cofounder conversation — Get data to back up equity discussions
• When evaluating an acquisition offer — Know what your stake is truly worth

Common Dilution Mistakes

After helping founders model their equity, here are the most common mistakes we see:

1. Forgetting the option pool — Investors often require a 10-20% option pool. This dilutes you before the investment even happens.
2. Underestimating total dilution — Founders often calculate one round but forget to model all future rounds. The compounding effect is significant.
3. Ignoring SAFE conversion — SAFEs convert at a discount, which means more dilution than founders expect. Use our SAFE calculator to model this.
4. Not benchmarking — Without comparing to industry averages, you can't tell if your terms are competitive.
5. Over-optimizing for control — Some dilution is the cost of growth. The goal is smart dilution, not zero dilution.

Run Your Free Dilution Calculation Now →

Enter your startup details. See your ownership after every funding round. 60 seconds, no signup.

The Bottom Line

Your equity is the reward for years of startup building. Every percentage point matters — at a $100M exit, 1% is worth $1 million. Don't make equity decisions blind.

A free equity dilution calculator takes 60 seconds and gives you clarity on your most valuable asset. Whether you're raising your first round or planning your fifth, knowing your ownership trajectory is essential for making smart decisions.

More equity resources: Equity Cheat Sheet · Equity Glossary · Equity Benchmarks · All Free Tools