How much of the company will we own after each round?
Enter the pre-money valuation, the amount raised and the option pool for up to three rounds, and see who owns what after each one.
When a company sells new shares, everyone who already holds shares owns a smaller percentage. This is dilution. The number of shares you hold stays the same, but the total number of shares goes up.
The pre-money valuation is what the company is valued at before the new money goes in. Add the amount raised and you get the post-money valuation. The new investors own the amount they put in divided by the post-money valuation.
Investors often ask for an option pool, shares set aside for future staff, to be in place before they invest. It then comes out of the existing shareholders' share, not the new investors'. This calculator works it out that way.
Results
- Founders
- Option pool
- Round 1 investors
- Round 2 investors
| Holder | Now | After round 1 | After round 2 |
|---|---|---|---|
| Founders | 100.0% | 70.0% | 52.9% |
| Option pool | – | 10.0% | 12.0% |
| Round 1 investors | – | 20.0% | 15.1% |
| Round 2 investors | – | – | 20.0% |
| Post-money valuation | – | £2,500,000 | £10,000,000 |
| Added to the option pool | – | 10.0% | 4.4% |
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Worked example: a seed round, then a Series A
A made-up example: the founders own all the shares. They raise £500,000 at a £2 million pre-money valuation with a 10% option pool, then £2 million at an £8 million pre-money valuation with the pool topped up to 12%.
- Round 1: £2,000,000 pre-money + £500,000 raised
- £2,500,000 post-money
- New investors: £500,000 ÷ £2,500,000
- 20.0%
- Option pool topped up to 10%, before the money goes in
- + 10.0%
- Founders after round 1
- 70.0%
- Round 2: £8,000,000 pre-money + £2,000,000 raised
- £10,000,000 post-money
- New investors: £2,000,000 ÷ £10,000,000
- 20.0%
- Option pool topped up to 12%, before the money goes in
- + 4.4%
- Founders after round 2
- 52.9%
- Founders' shares at the last post-money valuation (on paper)
- £5,288,889
Without the option pool top-ups the founders would own 64.0% after the last round instead of 52.9%: the pool comes out of their share, not the new investors'.
Worth knowing
- A smaller share can still be worth more. If the company's value grows, a smaller slice of it can be worth more than the bigger slice you had before.
- The British Business Bank says many advisers think of giving away 10 to 20% in a first round, because later rounds will dilute the founders further.
- If a round's share price is lower than the last one (a down round), anti-dilution terms can give earlier investors extra shares. This calculator does not include those terms, or convertible loan notes and advance subscription agreements that turn into shares at a discount.
- By law, a company issuing new shares usually has to offer them first to its existing ordinary shareholders, in proportion to what they hold. These pre-emption rights can be excluded or switched off, and investors often ask for their own pro-rata rights to join later rounds.
- Many UK companies grant staff options through Enterprise Management Incentives (EMI), which have tax advantages. From 6 April 2026, a company can use EMI with gross assets of up to £120 million and fewer than 500 full-time employees, with up to £6 million of options in total and up to £250,000 for each employee over 3 years.
Routes this works for
Sources
- British Business Bank: What is a term sheet? (equity dilution worked example; option pool before investment dilutes the founders; pro-rata rights) · checked 8 October 2026
- British Business Bank: What is a cap table? (option pools, founder dilution) · checked 8 October 2026
- British Business Bank: How much equity should I offer to investors? · checked 8 October 2026
- Companies Act 2006, section 561: existing shareholders' right of pre-emption · checked 8 October 2026
- HMRC: Expanding the eligibility limits of the Enterprise Management Incentive scheme (from 6 April 2026) · checked 8 October 2026
- GOV.UK: Tax and employee share schemes, Enterprise Management Incentives (£250,000 per employee over 3 years) · checked 8 October 2026