Pre- and post-money valuation
A 2 million investment into a company valued at 8 million before the round makes it worth 10 million after, so the new investor owns 20% and existing holders keep 80%. Enter the investment and either valuation. Free in your browser.
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Worked example
- Investment
- 2,000,000
- Pre money
- 8,000,000
- Post money
- 10,000,000
- Investor ownership percent
- 20
- Existing ownership percent
- 80
- Given
- pre_money
A priced financing round is quoted as two valuations that differ by the cash that just went in: the pre-money valuation is the company's agreed value immediately before the new investment, and the post-money valuation is that same value after the cheque clears. Founders, angels, seed funds, and company counsel need both numbers from whichever one the term sheet already prints, plus a hard stop when the cheque would buy the whole company.
How pre-money, post-money, and the cheque lock together
Pre-money valuation is the agreed value of the company immediately before new shares are issued for the incoming cash. Post-money valuation is that same agreed value after the cash is counted: it is the denominator for the new investor's ownership. A seed cheque of two million into a company priced at eight million pre-money produces a ten million post-money company.
The new investor owns two million divided by ten million, which is twenty percent, and existing holders retain eight million divided by ten million, which is eighty percent. The same arithmetic runs backwards from a quoted post-money figure. A term sheet that prints a twenty million post-money valuation against a five million cheque implies a fifteen million pre-money valuation and a twenty-five percent investor stake.
The new investor's ownership is always investment divided by post-money; the existing holders' fully diluted share immediately after close is pre-money divided by post-money. Those two percentages add to one hundred. This calculator does not model an option-pool shuffle, a convertible-note conversion, or a SAFE that converts at a discount or a valuation cap: those steps change the share count before this identity is applied, and they are a different search.
You supply the investment amount and one of the two valuations; the calculator fills the missing valuation and reports both ownership percentages. Money fields are rounded half-up to cents so goldens compare byte-for-byte across runtimes. A round whose investment equals or exceeds the post-money number would imply a non-positive pre-money and an investor stake of one hundred percent or more, which is not a priced round, so that case is rejected rather than returned as a zero or negative company value.
Where a pre- and post-money valuation calculator earns its keep
Founders screening a term sheet use a pre- and post-money valuation calculator to turn the cheque and the one number counsel already wrote into both valuations and both ownership percentages before they open a full cap-table workbook. Company counsel drop investment from the stock-purchase agreement and the quoted valuation from the recitals, and they check that the cheque is strictly smaller than post-money rather than treating a one-hundred-percent primary round as a priced deal.
This is a different search and a different job from a times-earnings business valuation, from a discounted-cash-flow model, and from carried interest: those tools scale a year of profit, discount a forecast, or split fund profits after a hurdle. Pre-money and post-money price a financing round. Failed validation does not consume balance.
Keep investment strictly below post-money, pin the rounded currency fields in tests, and you get a reproducible round price for data rooms, LMS plugins, and edge workers without modelling convertibles or option-pool shuffles of your own.
What you can do with it
Term-sheet screen before a cap-table rebuild
Turn the cheque and the one quoted valuation into both pre-money and post-money, plus implied ownership, before you open a full share ledger.
FAQ
Does this include an option-pool shuffle or SAFE conversion?
No. Option-pool shuffles, convertible notes, and SAFEs that convert at a discount or cap change the share count before this identity is applied. Those are different searches. This calculator prices the round you already described.
How do I get the pre-money valuation from the post-money?
Subtract the investment from the post-money valuation. A company valued at 10 million after a 2 million round was valued at 8 million before it, and the calculator fills in that missing figure for you.
What percentage of the company does the new investor own?
The investment divided by the post-money valuation. A 2 million investment into a company worth 10 million after the round buys 20%. The pre-money figure only matters because it sets that post-money total.
How much do existing shareholders keep after the round?
The pre-money valuation divided by the post-money valuation, measured right after the close. With 8 million before and 10 million after, existing holders keep 80%, and the two shares always add up to 100%.
What if the investment is as large as the post-money valuation?
The calculator rejects it. An investment equal to or above the post-money figure would leave a pre-money value of zero or less and give the investor 100% or more, which is not a priced round.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/fin/pre-and-post-money-valuation \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"investment":2000000,"pre_money":8000000}'const res = await fetch("https://api.kit.forhosting.com/fin/pre-and-post-money-valuation", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"investment": 2000000,
"pre_money": 8000000
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/fin/pre-and-post-money-valuation",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"investment": 2000000,
"pre_money": 8000000
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/fin/pre-and-post-money-valuation", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"investment":2000000,"pre_money":8000000}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"investment":2000000,"pre_money":8000000}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/fin/pre-and-post-money-valuation", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"investment": 2000000,
"pre_money": 8000000
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "fin.pre_and_post_money_valuation",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
This pre- and post-money valuation calculator takes a strictly positive investment amount and the other given valuation — pre-money or post-money — and returns both sides of the identity post_money equals pre_money plus investment. When the investment equals or exceeds the post-money figure, the implied pre-money is zero or negative and the new money would own one hundred percent or more of the company, so the task fails with invalid_input and is not billed.
How pre-money, post-money, and the cheque lock together
The identity that every priced equity round uses is post_money equals pre_money plus investment.
Input contract, response shape, and error behaviour
POST a JSON body with a strictly positive investment and at least one of the two valuations. investment is the new money in one currency unit; aliases investment_amount, amount, and round_size map to the same field so a term-sheet column can keep its name. pre_money is the agreed company value immediately before the round; aliases premoney, pre_money_valuation, and pre are accepted. post_money is the agreed company value immediately after the round; aliases postmoney, post_money_valuation, and post are accepted. Provide pre_money, or post_money, or both. When only pre_money is sent the engine sets post_money equal to pre_money plus investment. When only post_money is sent the engine sets pre_money equal to post_money minus investment. When both are sent they must already satisfy that identity after rounding to cents; an inconsistent pair fails with invalid_input. Each numeric field may arrive as a JSON number or a numeric string. Missing investment, empty strings, and non-finite values fail with invalid_input naming the field. investment must be strictly greater than zero: a zero or negative cheque is not a priced round. pre_money, when provided, must also be strictly greater than zero, because a non-positive pre-money makes the new money equal or exceed the post-money value. On success the body echoes investment, pre_money, and post_money, all rounded half-up to cents, then reports investor_ownership_percent as investment over post_money times one hundred, existing_ownership_percent as pre_money over post_money times one hundred, given as which valuation was supplied (pre_money, post_money, or both), and a formula string restating the identity. Pair the JSON with your own cap-table work for option pools and convertibles; this endpoint prices the round you describe, it does not rebuild the share ledger.
Where a pre- and post-money valuation calculator earns its keep
Angels and seed funds re-run the same fields when the round size moves or the lead switches from a pre-money quote to a post-money quote, then pin pre_money and post_money in a data room so every investor conversation starts from one pair.
Integration use cases
Convert a post-money quote into pre-money for a data room
When the lead prints only post-money, fill pre_money from post_money minus investment and pin both figures so every investor conversation starts from one pair.
Reject a cheque that would buy the whole company
Fail fast with invalid_input when investment equals or exceeds post-money, instead of publishing a zero or negative pre-money as if it were a priced round.
Technical questions
How are pre-money and post-money valuation calculated?
post_money equals pre_money plus investment. Send a strictly positive investment and at least one of the two valuations; the calculator returns both, plus investor_ownership_percent as investment over post_money times one hundred. Money fields are rounded half-up to cents.
What happens if the investment equals or exceeds post-money valuation?
The task fails with invalid_input. investment must be strictly less than post-money: equality or excess implies a non-positive pre-money and an investor stake of one hundred percent or more, which is not a priced round. Those failures are not billed.
Do I have to provide both valuations?
No. Provide investment and the other given valuation — pre_money or post_money. You may send both if they already satisfy post_money equals pre_money plus investment; an inconsistent pair is invalid_input.
What does the pre- and post-money valuation calculator cost?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.