How much should a startup raise?
Raise too little and you are back in the market in eight months, negotiating with a clock on your back. Raise too much and you give away equity for cash you cannot use well. So how much should a startup raise? Enough to reach the next milestone that changes your valuation, plus a buffer for the next fundraise, and no more.
Round size is a runway decision first and a valuation decision second. The practical method is to work backwards: decide the milestone, price the burn needed to reach it, add the months it takes to raise again, and subtract the cash you already hold.
The round-size formula
Amount to raise = planned net burn until the milestone + net burn during the next fundraise − cash on hand today.
Three inputs drive it:
1. Planned net burn: the average monthly net burn over the plan, not today's burn. If you will hire, the average is higher. 2. Fundraising buffer: plan on roughly 6 months of runway still on the clock when you start the next raise, because a process often takes several months. 3. Cash on hand: what is in the bank now, after known payables.
Net burn, not gross burn, is the right base, since revenue offsets spend. If you have not computed it yet, start with the burn rate formula.
A worked example: a $960K round
Assume a seed-stage SaaS team with $60,000 in the bank. The plan is 18 months to reach a milestone investors will pay for, with net burn averaging $40,000 per month as two engineers join. The plan therefore costs 18 × $40,000 = $720,000.
By month 18 net burn has grown to $50,000. A 6-month fundraising buffer at that rate costs 6 × $50,000 = $300,000. Total need: $720,000 + $300,000 = $1,020,000. Subtract the $60,000 already held: $960,000 to raise, which most teams would round to a $1,000,000 target.
These figures are illustrative. Replace them with your own hiring plan, and check the result in the runway calculator: ($60,000 + $960,000) ÷ $40,000 gives 25.5 months at the starting pace, which confirms the plan has room.
$720K
18 months × $40K average net burn
$300K
6-month buffer × $50K exit burn
−$60K
Cash already in the bank
$960K
Amount to raise
The raise-versus-dilution trade-off
Every extra month of runway costs equity. Holding the post-money valuation at an assumed $4,000,000, the ownership sold is simply the raise divided by the post-money: $480,000 sells 12 percent, $720,000 sells 18 percent and $960,000 sells 24 percent.
Post-money is rarely held constant in practice, since a bigger ask may be priced differently, so treat this as a sensitivity check, not a forecast. Its value is in making the cost of buffer visible: the last 6 months of runway in this example cost about 6 percentage points of ownership.
| 12 months of plan | 24 months of plan | |
|---|---|---|
| Funds needed at $40K/month | $480,000 | $960,000 |
| Ownership sold | 12% | 24% |
| Next raise starts | Almost immediately | After a full build cycle |
| Main risk | Raising from weakness | Over-hiring on idle cash |
Start from the milestone, not the cheque
Investors at the next stage pay for evidence, so define the proof point first: a revenue level, a retention curve, a signed pilot, or a regulatory approval. The round exists to fund that proof. A target such as "12 customers paying monthly" can be costed; "as much as possible" cannot.
Sector changes the clock. Health-Tech and Green-Tech milestones often take longer because approvals, pilots and capital purchases move slowly. Edu-Tech revenue follows the school calendar. If your milestone depends on a slow buyer, lengthen the plan before you size the round.
Mistakes that make rounds the wrong size
Sizing from today's burn is the most common error, since burn rises after the money arrives. Skipping the buffer is second: a team that raises exactly 18 months of cash has only 12 months to prove the milestone, because the raise itself takes the rest.
The opposite mistake is sizing to a round number or to what a friendly investor offers. A bigger cheque feels safe, yet it raises hiring pressure and raises the bar for the next round. Anchor on the plan, then compare it with the market, such as the typical pre-seed and seed ranges.
Practicing round-size decisions in Founder Runway
In Founder Runway, a run lasts 20 turns, and each decision has four options. Funding choices trade cash against equity across stages from Pre-Seed to Series A, so you can watch what happens when a round is a turn too small or a hire arrives too early.
Unlike Virtonomics-style economy sims, the pressure comes from realistic VC decision logic: investors read your trend, not just your balance. That makes it a safe place to rehearse the sizing conversation before it costs you real equity.
Frequently asked questions
How much should a startup raise in a seed round?
Raise enough to fund the plan to the next milestone plus about 6 months of buffer, minus cash on hand. For example, 18 months at $40,000 average net burn, a $300,000 buffer and $60,000 in the bank gives $960,000. Your own burn and milestone decide the number, not a market average.
How many months of runway should a raise cover?
Plan for the months needed to hit your milestone plus about 6 months to raise again. That often lands between 18 and 24 months in total. The buffer matters because a fundraise can take several months.
How do you calculate the amount to raise?
Add the planned net burn until your milestone to the net burn during the next fundraise, then subtract current cash. Use average planned burn rather than today's burn, since hiring raises it.
What happens if you raise too little?
You start the next raise with too little time, so investors see the deadline and may price you for urgency. You may also spend growth capital on survival tactics. A short clock is a negotiation weakness.
What happens if you raise too much?
You sell more ownership than needed and often hire faster than the business can absorb, which raises burn and the bar for the next round. Unused cash also raises the valuation expectations of the following investors.
Is round size the same as valuation?
No. Round size is the cash raised; valuation sets the price per share. Ownership sold equals the raise divided by the post-money valuation, so the same raise sells less equity at a higher valuation.
Test this decision in the game.
Apply the same assumption across one run and see which metric weakened three turns later.