Fundraising Finance Tool

Startup Dilution Calculator for Fundraising and Board Decks

Model priced-round dilution, post-money ownership, option-pool refresh impact, and board-ready ownership takeaways before you negotiate a fundraising round or take the cap-table story into an investor deck.

Live calculator

Use fully diluted shares and keep the option-pool assumption explicit.

Preset

Business Context

Management needs to show how much a new round and hiring pool top-up will dilute existing holders before approving a GTM expansion plan.

Audience

Founder, CFO, Series A board

Pre-Money Valuation ($m)Use the negotiated pre-money valuation for the priced round.New Money Raised ($m)Use the primary capital the company expects to raise in this round.Pre-Round Fully Diluted SharesInclude common, preferred, granted options, warrants, and any other shares counted in the pre-money fully diluted cap table.Unallocated Option Pool SharesOnly the ungranted pool. Do not include already-granted employee equity here again.Target Post-Money Option Pool (%)The target unallocated pool after the round closes. Set to 0 if no refresh is planned.

Immediate Output

Useful before signup, then ready to convert into a fundraising or board slide.

Price Per Share

$2.67

Implied by pre-money value and fully diluted shares.

New Investor Ownership

18.9%

Headline stake created by the new capital alone.

Option Pool After Refresh

10.0%

Unallocated pool remaining after the round closes.

Total Dilution To Pre-Money Holders

24.4%

Includes both new-investor shares and option-pool top-up.

Post-Money Valuation

$50.0M

Pre-money plus primary capital raised.

Post-Money FD Shares

19.83m

Total fully diluted shares after issuing round and pool top-up shares.

Interpretation

The new-investor ownership of 18.9% sits inside the usual series a range. The real board discussion is whether the milestone bought by the round justifies the option-pool refresh as well.

Board-Ready Takeaway

A $10.0M raise on a $40.0M pre-money implies $2.67 per share and 18.9% new investor ownership. Refreshing the unallocated option pool to 10% leaves pre-money holders at 75.6% post-close, with total dilution of 24.4%.

Formula and cap-table breakdown

Keep the math explicit so the negotiation stays analytical instead of anecdotal.

Price per share = pre-money valuation / pre-round fully diluted shares

Investor shares = new money raised / price per share

Option pool top-up = max(0, ((target pool % x (pre-round FD shares + investor shares)) - existing pool shares) / (1 - target pool %))

Post-money FD shares = pre-round FD shares + investor shares + option pool top-up

Round mechanics

Pre-money valuation = $40.0M

New money raised = $10.0M

Post-money valuation = $50.0M

Share counts

Pre-round FD shares = 15.00m

Investor shares issued = 3.75m

Option-pool top-up shares = 1.08m

Ownership output

Pre-money holders post-close = 75.6%

New investors post-close = 18.9%

Unallocated pool post-close = 10.0%

Dilution bridge

Financing dilution = 18.9%

Option-pool dilution = 5.5%

Total dilution = 24.4%

Typical ownership ranges by round

These are sanity-check ranges, not rules. The milestone bought by the round matters more than any single benchmark.

Round	Typical investor stake	Notes
Seed	12% to 20%	Seed rounds often land here when the company is still buying time, proof points, and hiring capacity rather than optimizing purely for ownership efficiency.
Series A	15% to 25%	Series A boards usually tolerate mid-teens to mid-twenties dilution when the round clearly funds the next repeatable GTM and product milestones.
Series B	10% to 18%	Later rounds often tighten the dilution target because the company should already have more proof, more leverage, and more pricing power with investors.
Growth / extension	5% to 12%	Extension rounds, insider rounds, and growth rounds are often judged against lower dilution because management should be protecting ownership while still buying runway.

Post-Money Cap Table View

This is usually the fastest way to turn the calculator result into a board or investor slide.

Holder group	Shares	Post-money ownership
Pre-money holders	15.00m	75.6%
New investors	3.75m	18.9%
Unallocated option pool	1.98m	10.0%

Deck storyline

18.9% investor ownership is the headline number

Lead with the clean new-investor stake first because that is the number boards, founders, and funds instinctively anchor on.

Simple post-money cap-table table or ownership donut.

Deck storyline

5.5% of dilution comes from pool top-up

Separate the hiring-pool refresh from the financing itself so the board can debate whether the pool size is really required now.

Dilution bridge with investor dilution and option-pool dilution as separate bars.

Deck storyline

75.6% remains with pre-money holders after close

Frame the round as an ownership trade: what milestone, runway, or negotiating leverage does the company buy in exchange for that retained stake.

Action-title summary tile plus use-of-funds or milestone timeline.

Worked Example

Default scenario: B2B SaaS Series A. This gives you a realistic fundraising example to adapt for a board memo, founder update, or investor discussion.

Pre-money share price = $40.0M / 15.00m = $2.67.

Investor shares issued = $10.0M / $2.67 = 3.75m.

Option-pool top-up shares = 1.08m, which refreshes the pool to 10.0% post-close.

Total dilution to pre-money holders = 24.4%, leaving them with 75.6% of the company after the round.

Common Mistakes

Quoting only the investor ownership percentage and forgetting that the option-pool refresh also dilutes pre-money holders.
Modeling dilution on basic shares instead of fully diluted shares, which usually makes the founder ownership look artificially strong.
Treating the round as a cap-table exercise without tying the capital to the actual milestone or runway being purchased.
Using an option-pool target with no hiring plan behind it, which invites board pushback on unnecessary dilution.
Ignoring that SAFEs, notes, or anti-dilution terms may make the final ownership split worse than the clean priced-round case shown here.

What this helps answer

How much of the company does the new round sell?

How much extra dilution comes from refreshing the unallocated option pool?

What post-money ownership remains with existing holders after the close?

When teams use it

Board prep before approving a financing strategy.

Founder and CFO cap-table planning before term-sheet negotiation.

Investor updates that need a clean explanation of use of funds and ownership trade-offs.

Assumptions

Priced equity round, not SAFEs or convertible debt.

Pre-money valuation negotiated on a fully diluted basis.

Option-pool refresh modeled as incremental dilution to reach the post-money target.

Related Resources

Investor Update Deck Generator

Turn the dilution math into an investor-ready slide with wins, risks, asks, and milestone framing.

Pitch Deck Grader

Audit whether the rest of the fundraising deck is strong enough before you show ownership and round mechanics.

Series B Fundraising Template

Package dilution, use of funds, milestones, and the raise ask inside a clean fundraising structure.

Investor Update Presentation Guide

See how founders frame runway, ownership trade-offs, and decision asks in a tighter board or investor narrative.

Startup Pitch Deck Structure

Use the dilution output inside a sharper fundraising story with the right slide order and proof points.

FAQ

What does this dilution calculator assume?

It assumes a priced equity round where the pre-money valuation is negotiated on a fully diluted basis, then new investor shares and any option-pool top-up are added to reach the post-money cap table.

Why does the option pool refresh matter so much?

Because investors often ask the company to top up the unallocated option pool before or as part of the round. That extra pool usually dilutes existing holders too, so the round dilution is often higher than the headline investor ownership alone.

Does this handle SAFEs, convertibles, or liquidation preferences?

No. This page is intentionally a clean priced-round calculator. SAFEs, notes, participating preferences, warrants, and side letters can change the economics and should be modeled separately.

Should founders present dilution as a single number?

Not usually. A better board slide separates investor dilution, option-pool dilution, and the resulting post-money ownership mix so stakeholders can debate the trade-offs explicitly.

When is a higher-dilution round acceptable?

When the capital clearly buys a meaningful milestone: product completion, enterprise readiness, a fundraise bridge, or enough runway to avoid raising again from a weak negotiating position.

Turn the ownership math into an executive slide

Once the dilution math is directionally right, XLSlides can turn it into a clean fundraising or board slide with action-title headlines, cap-table visuals, milestone framing, and a sharper decision ask.

Explore adjacent tool