Startup valuation calculator

When an investor offers money for a share of the company, the offer sets a valuation: investment ÷ share bought = post-money valuation. Take the investment off for the pre-money.

The formula

Valuation = investment ÷ share of the company it buys

Worked example: £1,000,000 post-money

The example uses the guide's seed round, £200,000 for 20%, with a matching cap table, exit, fund and market.

£200,000 ÷ 20% = £1,000,000 post-money
£1,000,000 − £200,000 = £800,000 pre-money

Try it with your numbers

Work out your valuation

It starts on the example. Replace any figure with your own; nothing you type leaves your browser.

Your deal numbers

Start with any one figure. Each one you add works out more below. Your numbers are kept in this browser only.

What this calculation uses

Investment offered (needed)

For this share of the company (needed)

Add more of your numbers

Open a group to fill it in. Everything you add shows up in the list below the calculator.

Your round

Pre-money valuation

You can type 2m or 750k.

New investment

Shares in issue

Options already granted

Unallocated option pool

In shares. 0 if you have none.

Option pool wanted after the round

Your own shares

Money converting at the round

Amount converting

From an ASA, SAFE or loan note.

Valuation cap

Leave blank for no cap.

Discount

Interest a year (loan notes)

Months since the note was issued

A sale of the company

Sale price of the company

What the preferred investor put in

What the preferred investor owns

1x2x

Participating preference

What the founders own

An investor's return

Amount invested

Share bought

Later dilution

30 means later rounds shrink that share by 30%.

Sale price at the exit

Years to the exit

The next round

Share you own now

Size of the next round

Its pre-money valuation

Last round's post-money

New round's pre-money

A venture fund

Fund size (committed)

Paid in by investors so far

Invested in companies so far

Paid back to investors

Value of what the fund still holds

Your market

Potential customers

What one pays a year

Share you can serve

Share of those you could win

A SEIS, EIS or VCT investment

Amount an investor puts in

Shares that vest

Shares or options granted

Vesting period

Cliff

Months worked so far

Your valuation

£1,000,000

post-money

£200,000 ÷ 20% = £1,000,000 post-money
£1,000,000 − £200,000 = £800,000 pre-money

Formula: Investment ÷ share of the company it buys.

Pre-money: £800,000
You keep: 80%

How to read your result

At an early stage the valuation is a negotiation, not a formula. This shows what an offer implies, so you can compare offers on the same basis.

Watch out for

Check whether the share is of the shares in issue or fully diluted, and whether an option pool comes out of the pre-money.

Last checked 24 October 2026. Estimates only, not financial, tax or legal advice: check your accounts and documents, and take advice before you act. More terms in the startup glossary.