How much of your company will you still own at Series C? This free founder dilution calculator models every round you raise (friends & family, pre-seed, seed, and each lettered round) and shows founder ownership after each one, like a cap table simulator without the spreadsheet. Every round is prefilled with typical market numbers, so you start from a realistic path and then change it to match your plans. No signup, and we don’t capture any data from your entries.
Add your first round to see founder ownership over time.
How this is calculated
Each priced round: new investors receive amount raised ÷ post-money valuation, and the option pool top-up is carved out before the round closes (the "option pool shuffle"), so both dilute everyone who came before (founders, earlier investors, and the existing pool) pro-rata. Founder ownership compounds round over round. Stage defaults are SVJ editorial benchmarks for typical US venture rounds (reviewed July 2026); SAFEs are modeled as if converting at the round shown. Educational estimates, not legal or financial advice.
How to use this calculator
- Start from the prefilled path. A typical pre-seed → seed → Series A path loads automatically. Edit any raise amount, pre-money valuation, or pool top-up to match your plan, or remove rounds you will skip.
- Add rounds as you go. The next stage is added with typical numbers for that stage (SVJ editorial benchmarks, reviewed July 2026).
- Watch the founder bar shrink. The table shows ownership after every round and each round’s total dilution (new investors plus pool top-up).
- Bookmark your plan. “Copy shareable link” saves every round in the URL. Keep it, update it with each raise, and send it to co-founders. It works as your dilution plan without creating an account.
- Finish at the exit. One click carries your final ownership and preference stack into the startup exit calculator.
Founder dilution by round: what is typical?
Rules of thumb for US venture rounds: each priced round sells 15 to 25% of the company, and option pool top-ups add another 5 to 10% at the early stages. Carta’s Q2 2026 benchmarks put median dilution at 19.4% for seed rounds and 18.7% for Series A (sources: Carta’s seed and Series A guides, October 2026). Compounding is what surprises founders. Three rounds at 20% each do not cost 60%. They leave founders with 0.8 × 0.8 × 0.8 ≈ 51% of what they started with, and the default path above (pre-seed through Series A with pool top-ups) lands founders at about 44%. By a typical Series C, founder ownership in the 15 to 25% range is normal. That is why the exit structure, as well as the exit price, decides what founders take home.
The terms, in plain English
Round dilution
New investors receive amount raised ÷ post-money valuation. Raise $3M at $12M pre-money ($15M post) and the round sells 20%. Everyone who held a stake before the round (founders, earlier investors, the option pool) is diluted by that 20% plus any pool top-up.
Pool top-up
Lead investors usually require the employee option pool refreshed to ~10% before their money comes in, so the top-up dilutes existing holders rather than the new investor (the “option pool shuffle”). In this calculator, the number you enter is the new pool added that round, on top of whatever pool remains from earlier rounds. It is not a target the total pool is refreshed to. Across all your rounds, pool top-ups quietly cost founders as much as an entire extra round.
Why earlier rounds hurt more
Dilution compounds multiplicatively, so the 10% you sell at friends & family is diluted again by every later round. Early equity is your most expensive equity, which is the argument for raising only what each stage needs rather than the maximum available.
Frequently asked questions
How much ownership do founders have after Series A?
A typical path (10% friends & family or pre-seed, ~20% seed with a pool top-up, ~20% Series A with a pool top-up) leaves the founding team around 40 to 50% combined after Series A. How that is split depends on whether there is one founder or several.
How much equity do founders give up in each round?
Market norms: friends & family 5 to 10%, pre-seed ~10%, seed 15 to 25%, Series A 15 to 25%, and later rounds 10 to 20% each, shrinking as the company grows into its valuation. Selling much more than 25% in one round signals that something is off, usually the valuation.
Does this model SAFEs?
Treat a SAFE round as a priced round at its post-money valuation cap. For post-money SAFEs, that is exactly the ownership the investor locks in. For precise multi-SAFE modeling with discounts and a conversion round, use the SAFE dilution calculator and bring the result back here.
How accurate is this founder dilution calculator?
The round math (investment ÷ post-money, pool carved pre-money) is the standard venture model. The stage defaults are editorial benchmarks for typical US rounds, and your market, sector, and negotiating leverage will differ. The calculator works at the percentage level, not with share-level cap table math. It is educational, not legal or financial advice.
If you are new to the funding stages, read our guide to the startup funding stages, price your next round with the valuation calculator, and see all our free startup tools.