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Pro Rata Calculator

Find the check that keeps your ownership in a new round, what you will own if you skip it, and what a smaller check gets you.

Inputs

Reset

Your position

Fully diluted, before the new round

New round

Total new money, including pro rata checks

Your check

0 to see the skip scenario only

Results

Pro rata check to keep 2.00%

$200,000

2.00% of the $10M round, buying 0.40% of the company at $50M post-money

Ownership if you skip
1.60%
Down 0.40 points
Ownership with your check
1.80%
$100K is 50% of your pro rata
Share the round sells
20.0%
$10M / $50M post-money
Pre-money valuation
$40,000,000
Stake at post-money if you skip
$800,000
Stake at post-money with your check
$900,000
Includes your $100K check
Your ownership after the round

Track pro rata in Raziel

See your ownership in every company and plan follow-on checks before the round closes.

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The math

How pro rata works

Every priced round sells a slice of the company to new money, and everyone who already owns shares gets diluted by that slice. A pro rata right lets you buy back in.

  1. Size the round. The round sells its size divided by the post-money valuation. That is how much everyone else shrinks.
  2. Take your share of it. Buying your current percentage of the new shares (your ownership times the round size) exactly offsets the dilution.
  3. Or write a different check. Any check buys check divided by post-money of the company, on top of your diluted stake.
Round stake          = round size / post-money
Pro rata check       = ownership x round size
Ownership if skipped = ownership x (1 - round stake)
Ownership with check = ownership if skipped + check / post-money

Assumptions and simplifications

  • Your pro rata check is part of the round size, not on top of it.
  • No option pool increase, SAFE or note conversion in the round. Those dilute you further; see the option pool and SAFE conversion calculators.
  • Stake values use the post-money valuation, before any liquidation preferences.

Worked example

2% owner, $10M round at $50M post-money

Round stake
$10M / $50M = 20.0%
Pro rata check
2% x $10M = $200,000
If you skip
2% x 80% = 1.60%
With a $100K check
1.60% + $100K / $50M = 1.80%
Pro rata check$200,000

Further reading

Frequently Asked Questions

Common questions about the Pro Rata calculator and the math behind it.

What is a pro rata right?

A right, usually in a side letter or the investor rights agreement, to buy enough of a future round to keep your percentage ownership. If you own 2% and the company raises $10M, your pro rata is 2% of the round, or $200,000.

How is the pro rata amount calculated?

Your current fully diluted ownership times the size of the new round. Buying that share of the new stock exactly offsets the dilution from the round, so your percentage stays the same afterward.

What happens if I skip my pro rata?

Your ownership falls by the share of the company the round sells. A round that sells 20% of the company takes a 2% holder to 1.6%. You keep the same number of shares, and if the round is priced up they are worth more on paper.

Should I always take my pro rata?

Not automatically. Following on concentrates more money in one company at a higher price. Many investors take pro rata in the companies that are clearly working and pass on the rest. This calculator shows the ownership math; the investment decision is yours.

Does the option pool affect my pro rata?

If the round also tops up the option pool before the new money comes in, you are diluted by the pool increase as well, and your pro rata check will not fully restore your ownership. Pro rata rights are usually defined on the new securities sold, not the pool. Use the option pool calculator to see that effect.

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