Bridge Round Dilution Calculator

Background.

Bridge Round Dilution Calculator supports a concrete decision: use it to estimate new ownership and shares from a priced interim equity round. The result needs one precise interpretation: a bridge equity round uses a pre-money fully diluted share price and post-money ownership just like another priced issuance. The selected relationship is “bridge investor ownership = bridge investment / post-money valuation; new shares use the pre-money fully diluted share price.”

The editable entries are bridge-round pre-money valuation, bridge-round primary investment, pre-bridge fully diluted shares. Use values from the document or measurement that governs this bridge round dilution question; the defaults are only the worked fixture below. If the bridge is actually a note or SAFE, conversion, interest and cap mechanics make this the wrong model. The bridge round dilution calculation does not infer that fact from the other entries.

National Venture Capital Association, Model Legal Documents; preferred-stock financing terms documents the convention or governing rule used here. The bridge round dilution output is a transparent scenario under those facts: it does not manufacture an unentered market price, professional determination, carrier quote, legal eligibility finding or locally adopted code value.

What is bridge round dilution calculator?

Bridge Round Dilution is the relationship behind this decision: a bridge equity round uses a pre-money fully diluted share price and post-money ownership just like another priced issuance. On this page it means bridge investor ownership = bridge investment / post-money valuation; new shares use the pre-money fully diluted share price. If the bridge is actually a note or SAFE, conversion, interest and cap mechanics make this the wrong model; that is the line between the reported quantity and a broader corporate finance analysis.

How to use this calculator.

1. 01Confirm that “bridge investor ownership = bridge investment / post-money valuation; new shares use the pre-money fully diluted share price” matches the bridge round dilution convention you need.
2. 02Replace the fixture values for bridge-round pre-money valuation, bridge-round primary investment, pre-bridge fully diluted shares with dated values from the governing record.
3. 03Keep all currencies, measurement units and time periods on the same basis before calculating.
4. 04Read bridge investor post-money ownership together with this boundary: If the bridge is actually a note or SAFE, conversion, interest and cap mechanics make this the wrong model.

The formula.

The calculation uses bridge investor ownership = bridge investment / post-money valuation; new shares use the pre-money fully diluted share price. In this bridge round dilution model, the entered terms are bridge-round pre-money valuation, bridge-round primary investment, pre-bridge fully diluted shares. A bridge equity round uses a pre-money fully diluted share price and post-money ownership just like another priced issuance, which is why the relationship is presented under this name rather than as a universal alternative. If the bridge is actually a note or SAFE, conversion, interest and cap mechanics make this the wrong model. Calculations keep full decimal precision through the relationship and round only the returned display values.

A worked example.

Frequently asked questions.

References& sources.

1. [1]National Venture Capital Association, Model Legal Documents; preferred-stock financing terms. Retrieved 2026-08-07. access: open unless marked otherwise.
2. [2]U.S. Securities and Exchange Commission. Investor.gov glossary: Dilution. Retrieved 2026-08-07. independence: primary; access: open.
3. [3]U.S. Securities and Exchange Commission. Investor.gov glossary: Convertible securities. Retrieved 2026-08-07. independence: primary; access: open.