PureBuild is a collection of free, deterministic calculators designed for startup founders and builders. Our tools help you make data-driven decisions about equity, dilution, runway, unit economics, and more.

Are PureBuild tools really free?

Yes, all PureBuild tools are completely free to use. No sign-up required, no hidden fees, no premium tiers. We believe essential business calculations should be accessible to everyone.

Do I need to create an account?

No. All PureBuild tools work without any sign-up or registration. Your data stays in your browser and is never sent to our servers.

What tools does PureBuild offer?

PureBuild offers 9+ specialized calculators including: Equity Calculator, Dilution Simulator, Runway Calculator, Unit Economics Modeler, Payment Gateway Fee Calculator, API Token Cost Estimator, Database Capacity Planner, Viral Coefficient Calculator, and True Hourly Rate Calculator.

How do I calculate dilution from a funding round?

Dilution = Investment Amount ÷ Post-Money Valuation. If an investor puts in $2M at a $10M post-money valuation, they get 20% of the company, and all existing shareholders are diluted by 20%.

What is anti-dilution protection?

Anti-dilution provisions protect investors if the company raises money at a lower valuation later (a "down round"). Common types include full ratchet and weighted average anti-dilution.

How much dilution is normal per round?

Typical dilution is 15-25% per funding round. Seed rounds often see 15-20% dilution, while Series A might be 20-25%. By Series C, founders often retain 15-30% total.

How do I calculate dilution from a funding round?

Dilution = Investment Amount ÷ Post-Money Valuation. If an investor puts in $2M at a $10M post-money valuation, they get 20% of the company, and all existing shareholders are diluted by 20%.

What is anti-dilution protection?

Anti-dilution provisions protect investors if the company raises money at a lower valuation later (a "down round"). Common types include full ratchet and weighted average anti-dilution.

How much dilution is normal per round?

Typical dilution is 15-25% per funding round. Seed rounds often see 15-20% dilution, while Series A might be 20-25%. By Series C, founders often retain 15-30% total.

Equity Dilution Calculator: Model Funding Round Impact on Ownership

PUREBUILD DS-3000

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Last updated: 2025-01

Equity Calculator

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→ Understanding Dilution Logic → The Math Behind Startup Equity

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Frequently Asked Questions

Equity dilution occurs when a company issues new shares, reducing existing shareholders' ownership percentage. For example, if you own 10% and the company issues new shares to investors, your percentage decreases even though your share count stays the same.

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