---
title: "What Is Note Conversion Math?"
term: "Note Conversion Math"
description: "Note conversion math is the calculation that determines how many shares a convertible note or SAFE converts into at a priced equity round — applying valuation cap, discount, and interest accrual rules."
date: 2026-07-25T00:00:00.000Z
updated: 2026-07-25T00:00:00.000Z
topics: ["venture-capital"]
source: https://venturecapitaltracker.com/glossary/note-conversion-math
---

# What Is Note Conversion Math?

> Note conversion math is the calculation that determines how many shares a convertible note or SAFE converts into at a priced equity round — applying valuation cap, discount, and interest accrual rules.

**Note conversion math** is how convertible instruments translate invested dollars into shares when a qualifying equity financing triggers conversion.

### How it works

A note has $500K principal, 6% simple interest, $8M valuation cap, and 20% discount. Series A prices at $12M pre-money. Cap price implies ownership as if the company were worth $8M; discount price is 80% of Series A price per share. The noteholder converts at whichever yields **more shares** — usually the cap when the round valuation exceeds the cap.

Interest often adds to principal before division. Example: $530K converts at cap-implied price → share count = $530K / (cap-based price per share). Multiple notes convert simultaneously; **pro-rata** side letters may grant additional investment rights in the priced round.

SAFEs skip interest but use similar cap/discount mechanics. MFN (most favored nation) SAFEs adopt best terms from later SAFEs — complicating manual math without a model, especially when multiple bridges close at different caps before Series A.

### Why it matters

- **Founders:** Run a full cap table model before signing term sheets. Uncapped stacks from multiple bridges can leave surprisingly little founder ownership after Series A.
- **Investors:** Verify conversion price, whether pre-money or post-money SAFEs dilute differently, and that qualified financing thresholds actually trigger conversion.

### Common mistake

Using headline Series A valuation without subtracting note conversion shares from pre-money — priced round share counts depend on fully diluted capitalization including converted notes.

### Related ideas

See also [KISS note](/glossary/kiss-note), SAFE, valuation cap, and [cap table](/glossary/cap-table) modeling.

## FAQ

### What is Note Conversion Math in simple terms?

When a priced round happens, each note holder converts at the better price for them — usually the lower of the cap price or the discounted round price — plus any accrued interest added to principal. That yields their share count.

### Why does Note Conversion Math matter?

For founders, stacked notes and SAFEs can dilute more than expected if you ignore cap and discount stacking. For note investors, conversion math determines ownership entering the priced round and pro-rata rights downstream.


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Source: https://venturecapitaltracker.com/glossary/note-conversion-math