Pre and Post Money Valuation Calculator for Startups
Estimate startup valuation, ownership, newly issued shares, and dilution.
Enter pre-money value, new investment, existing shares, and the pre-investment price per share.
About the Pre and Post Money Valuation Calculator
Startup priced rounds are usually discussed with two related numbers. Pre-money valuation is the agreed value of the company before the new cash is added. Post-money valuation is that figure plus the investment. If a company is worth $1,000,000 before a $250,000 check, post-money value is $1,250,000 and the new investor’s ownership on a simple common-stock model is 20 percent. Founders also need the share count: new shares equal the investment divided by the pre-investment price per share, and those shares are added to the existing total. Formula: post-money = pre-money + investment; new shares = investment ÷ price per share; total shares after = existing shares + new shares; investor ownership % = new shares ÷ total shares after × 100; existing-shareholder dilution % = 100 − existing shares ÷ total shares after × 100. On a consistent cap table, pre-money should equal existing shares × price per share. The calculator does not force that identity. Ownership and dilution are computed only from shares and price, while post-money is computed only from pre-money plus cash. If those two views disagree, the ownership percentage will not equal investment ÷ post-money. A priced round is rarely this simple. Option-pool top-ups may be carved from pre-money or post-money, converting notes and SAFEs can inject extra shares, and preferred stock often carries liquidation preferences that make economic ownership differ from percent of common. Share counts may be basic or fully diluted. Price per share should use the same basis as the share count you enter. Use the pre and post money valuation calculator to sketch a clean common-stock round, then layer legal terms separately. Typical uses include comparing a seed check at two pre-money levels, estimating how many new shares a follow-on creates, and showing existing holders how much a round dilutes them. Change one input at a time so you can see whether a higher price or a smaller raise is driving ownership. The result is a planning estimate, not a term sheet, 409A appraisal, or tax opinion. Confirm authorized shares, option-pool treatment, and conversion mechanics with counsel before signing.
Pre-money and post-money examples
Simple priced-round illustrations using the calculator’s share-count math.
| Inputs | Output | Note |
|---|---|---|
| $1,000,000 pre-money; $250,000 investment; 100,000 shares at $10 | Post-money $1,250,000.00; 20.00% ownership; 25,000 new shares | Pre-money equals shares times price, so ownership also equals investment divided by post-money. |
| $5,000,000 pre-money; $1,000,000 investment; 500,000 shares at $10 | Post-money $6,000,000.00; 16.67% ownership; 100,000 new shares | A larger round at a consistent $10 price. |
| $2,000,000 pre-money; $1,000,000 investment; 200,000 shares at $5 | Post-money $3,000,000.00; 50.00% ownership; 200,000 new shares | Shares times price equal $1,000,000, which does not match the $2,000,000 pre-money input. |
How to calculate pre-money and post-money valuation
- Enter the agreed pre-money valuation and the new investment amount.
- Enter the existing share count and the pre-investment price per share on the same basis.
- Select Calculate to review post-money value, new shares, ownership, and dilution.
- Check that pre-money is close to shares times price if you want ownership to match cash-on-cash percentage.
Pre and post money valuation FAQ
What is the difference between pre-money and post-money valuation?
Pre-money is the company value before the new cash. Post-money adds the investment to that figure and is the denominator people often use when quoting the investor’s percent of the company.
How are new shares calculated?
New shares equal the investment divided by the stated pre-investment price per share. Those shares are added to the current share count to produce the total after the round.
Why might ownership not equal investment divided by post-money?
Ownership uses share counts, while post-money uses the pre-money plus cash. If pre-money is not equal to existing shares times price, the two percentages diverge.
Does this include an option pool or convertibles?
No. Option-pool refreshes, SAFEs, notes, and preferred preferences are omitted. Model those terms separately before treating the ownership figure as fully diluted.
Is this a substitute for a term sheet?
No. Use it to understand the arithmetic of a clean priced round. Legal documents, cap-table software, and counsel should govern any actual issuance.