Free tool · No sign-up required

Multi-SAFE batch conversion simulator.

Stack as many post-money SAFEs as you have outstanding. Each converts at its own lower-of-cap-or-discount price, and the math reconciles across all of them simultaneously. The hardest piece of round-closing math, solved.

  • Unlimited SAFEs, each with their own cap and discount
  • Per-SAFE conversion price, share count, and post-round ownership
  • Updates live as you type, no email required to use it
  • Optional emailed PDF report with the per-SAFE breakdown
Open the simulator
Inputs & results

Add SAFEs, enter round terms, see how the batch converts. Uses post-money SAFE conversion mechanics from Y Combinator’s 2018 template.

Company
Total fully-diluted shares outstanding before any SAFE.
SAFEs outstanding 0 SAFEs
Priced round
$
$
%
Top-up comes out of the pre-money cap (founder + SAFE dilution).
Round math
Round price per share
—
Total SAFE money converting
—
SAFE shares (all SAFEs combined)
—
Total SAFE % post-round
—
Per-SAFE conversion
SAFE Cap Disc Conv. price Shares % post
Post-round cap table
StakeholderShares% post
Founders & existing holders——
All SAFE holders——
New round investors——
Option pool (top-up)——
Post-round fully diluted , 100.0%
Founders SAFE holders New investors Option pool
Optional · Save this scenario
Email me the per-SAFE breakdown as a PDF.

We’ll send a clean report with every SAFE’s conversion price and share count, the round math, and the post-round cap table, ready to share with co-founders or counsel.

We’ll send the PDF and occasional corporate-records tips. Unsubscribe any time. We don’t share your email.

How the math works

Batch SAFE conversion in five steps.

All your SAFEs convert at the same moment, but each one converts at its own price. The math is interdependent, that’s why a single-SAFE calculator falls apart when you have a stack.

1
Anchor the share count

Start from the pre-SAFE share count. Add the option pool top-up. This becomes the working base for every SAFE’s conversion price.

2
Round price per share

Pre-money valuation divided by the pre-round fully-diluted count (founders + all converted SAFEs + pool). That’s the price new investors pay.

3
Cap-based price, per SAFE

Each SAFE’s post-money cap divided by the pre-round share count. SAFEs with lower caps get cheaper shares than SAFEs with higher caps.

4
Discount-based price, per SAFE

Round price multiplied by (1 − that SAFE’s discount). Each SAFE converts at the lower of cap-based and discount-based price.

5
Reconcile across the stack

Every SAFE’s shares feed back into the pre-round share count, which changes every other SAFE’s price. The simulator iterates until everything is consistent.

Why this matters

Batch conversion is where hand-built cap tables fall apart.

One SAFE on a spreadsheet is doable. Five SAFEs with different caps, different discounts, an option-pool top-up, and a priced round on top, the algebra is interlocked, and rounding errors compound. Closing diligence finds those errors. Octelligence runs the conversion deterministically against your live register, so the round closes with records intact.

See Cap Tables & Financing
FAQ

Common questions

The single-SAFE simulator handles one SAFE at a time. This one stacks any number of SAFEs and solves the conversion simultaneously. If you only have one SAFE outstanding, either tool works; with two or more, only this one will give you the right answer.

No. All SAFEs convert simultaneously at the priced round, and the simulator iterates the math until everything reconciles. List them in any order, the result is identical.

This simulator takes the cap and discount you enter as final. If a SAFE has an MFN clause that pulls in the best terms from a later SAFE, update that earlier SAFE’s cap or discount manually before running the math. We’ll add automatic MFN handling in a future revision.

The simulator assumes all SAFEs are post-money (the YC 2018 form). Pre-money SAFEs convert against the pre-money cap, which is mechanically different. If you have a mix, run the pre-money SAFEs separately and treat their shares as part of the pre-SAFE count.

By convention, the pool top-up comes out of the pre-money cap, diluting founders and all SAFE holders before the new money lands. The simulator follows that convention, same as the single-SAFE version.

Request the PDF report above. Your inputs are stored client-side while the tab is open, so you can also bookmark and come back. For an audit-grade record, you want a real cap-table system, see Octelligence.
Related concepts

The glossary behind the batch.

Definitions of every term the simulator uses, plus the sibling tools for single-SAFE and full priced-round modeling.

SAFE (post-money)
The conversion form this simulator models
Valuation cap
The ceiling on each SAFE’s conversion price
Discount rate
The alternative pricing path per SAFE
MFN clause
How earlier SAFEs match later terms
Pro-rata rights
SAFE-holder rights in the next round
Cap table
Where the converted shares land
SAFE Conversion Simulator
Single-SAFE version with full step-through math
Cap Table Dilution Calculator
Model the priced round across all holders
Corporate Records Health Check
See if your records survive a closing
When the batch math has to be right.

Octelligence runs your cap table, share register, and certificates from one source of truth, so batch SAFE conversions reconcile automatically against the register the day the round closes.

Sign up See Cap Tables

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