How to Calculate Startup Runway Before Hiring New Employees

Two years ago I watched a founder hire three engineers in a single month because his bank balance looked healthy. Nine months later he was negotiating a bridge round at a valuation 40% below his last one. The bank balance was never the problem. The problem was that he'd never calculated how long that money actually had to last once three new salaries, payroll taxes and laptops entered the picture.

That's what this article is about: how to calculate startup runway before hiring, in a way that survives contact with reality. Not the tidy formula you'll find in a pitch deck template, but the version that accounts for severance risk, ramp-up time, and the fact that a new hire costs more in month one than the salary line suggests.

If you're sitting on 14 months of cash and wondering whether you can afford that senior hire, this is for you.

The runway formula, and why it lies to you

The textbook formula is simple: months of runway = current cash ÷ net monthly burn. Net burn is your monthly expenses minus monthly revenue. If you have $600,000 in the bank and you're burning $50,000 a month, you have 12 months.

Clean. Useless on its own.

Here's the thing: that formula assumes your burn stays flat. The moment you hire, it doesn't. And most founders calculate runway on the pre-hire burn, then mentally subtract a salary, then convince themselves the math works. I did exactly this in 2021 and it cost me a quarter of negotiating leverage when I had to raise.

Net burn vs. gross burn: which one do you use?

Gross burn is total monthly spending. Net burn is spending minus incoming revenue. For hiring decisions, always use net burn — but be honest about which revenue is actually recurring versus one-off.

A startup I advised last year counted a $40,000 annual contract as if it were monthly recurring revenue for runway purposes. Their "18 months of runway" was really closer to 11. When they hired two people against that inflated number, they ran out of options fast.

• Recurring subscription revenue: count it fully
• Signed contracts billed annually: divide by 12, don't front-load
• Pipeline and verbal commitments: count as zero
• One-off consulting or services: count only what's already invoiced

Why runway is a range, not a number

Any single runway figure is a point estimate built on assumptions that will be wrong. The useful output of a runway calculation is a range: "somewhere between 9 and 14 months." That range is what should drive the hiring decision, and it's also what you should be presenting to your board or your investors during due diligence.

Takeaway: calculate runway with net burn, and always express it as a range across scenarios.

The true cost of a hire (it's not the salary)

Here's where most runway calculations quietly fall apart. A $90,000 salary is not a $7,500 monthly cost. It's closer to $9,400 once you account for everything below.

Cost component	Typical range (US/EU)	One-off or recurring?
Gross salary	Baseline	Recurring
Employer payroll taxes & social contributions	15–30% of salary	Recurring
Health insurance / benefits	$400–$900/month	Recurring
Equipment (laptop, monitor, peripherals)	$2,000–$4,000	One-off
Software seats (Slack, Figma, IDE, etc.)	$100–$350/month	Recurring
Recruiting fee (agency)	15–25% of first-year salary	One-off

Add it up for a $90,000 hire in a mid-cost market and you're looking at roughly $113,000 in year one, or about $9,400 per month. That's a 25% premium over the salary line, and I've seen it hit 40% for senior roles with agency fees attached.

The ramp-up problem nobody budgets for

New hires don't produce value on day one. A senior engineer might take two to three months to become net-positive on output. A sales hire might take four to six months to close their first meaningful deal.

This means your effective runway cost isn't just the salary — it's the salary plus the opportunity cost of a period where output hasn't caught up to expense. In practice, I budget three months of pure cost for any hire before assuming they contribute to revenue or velocity.

What about contractors vs. full-time?

Contractors look cheaper on paper because you skip benefits and payroll taxes. But they carry their own runway risk: higher monthly rates, less commitment, and the ability to walk mid-project. For a 6-month runway situation, a contractor might genuinely be the right call. For a 24-month runway, a full-time hire usually wins on cost per unit of output.

Takeaway: multiply salary by 1.25–1.4 before it ever touches your runway math.

Building a three-scenario hiring model

This is the part that actually protects you. Instead of one runway number, build three. I keep this in a simple spreadsheet and update it on the first of every month.

If you want a broader framework for this kind of planning, it's worth reading up on business blueprints for startups — the discipline of documenting assumptions is what makes the model useful rather than decorative.

The three scenarios

1. Base case: revenue grows at your trailing 3-month average. Costs increase by the full new-hire cost.
2. Slow case: revenue stays flat for 6 months, then grows at half your average rate.
3. Worst case: revenue drops 15% and stays there. This isn't pessimism — it's the scenario that determines whether you survive a bad quarter and a new salary.

Run all three with and without the hire. The difference between the two is your runway cost of hiring. If the worst-case post-hire runway drops below 9 months, you don't hire yet. Full stop.

A worked example

Let's say you have $480,000 cash, $30,000 monthly revenue, and $70,000 monthly expenses. Pre-hire net burn is $40,000, so pre-hire runway is 12 months.

You want to hire someone at $90,000, which is $9,400/month fully loaded. New net burn: $49,400. New runway: 9.7 months.

In the base case, that's fine if revenue grows. In the worst case — revenue drops to $25,500 — net burn becomes $53,900 and runway drops to 8.9 months. That's below the safety threshold, and it means the hire is a bet on growth continuing. Sometimes that bet is correct. But you should know you're making it.

Takeaway: the number that matters is post-hire runway in the worst case, not the base case.

Setting hire triggers instead of guessing

Gut feel is a terrible hiring signal. So is "we're drowning." Both are real, but neither is a number. What works better is a pre-committed trigger: a specific condition that, when met, unlocks the hire.

I've used this for three years now and it's removed most of the agonizing. The trigger looks like this:

• Post-hire worst-case runway ≥ 12 months, and
• Trailing 3-month revenue covers at least 60% of the new hire's fully loaded cost, and
• The role has been a documented bottleneck for at least 6 weeks

All three conditions, not two. The third one matters because it filters out hires that feel urgent but aren't actually blocking revenue. If a role has been "needed" for six weeks and nothing has broken, it probably isn't the constraint you think it is.

How often should you recalculate runway?

Monthly, at minimum. Weekly if your revenue is volatile or you're within 6 months of a raise. The calculation itself takes 15 minutes once the spreadsheet exists. The cost of not doing it is discovering your runway is 4 months when you thought it was 8 — which is exactly the situation that forces bad terms on a bridge round.

For a deeper look at keeping cash resilient through these cycles, this piece on smart cash strategies is worth your time.

What if my revenue is lumpy or seasonal?

Then use a rolling 6-month average instead of 3, and add a seasonality adjustment. If Q1 is always your weakest quarter and you're hiring in December, your worst-case scenario needs to reflect that — not a smoothed annual average. I've watched two companies hire in Q4 against Q3 revenue and both had to make cuts by March.

Takeaway: write your hire trigger down before you're emotionally invested in a candidate.

When to break your own rules

Rules exist to protect you from yourself, but they aren't absolute. There are situations where hiring below your runway threshold is the correct decision, and pretending otherwise would be dishonest.

Two cases I've seen work:

1. The hire unlocks a signed or near-signed contract. If a specific customer commitment depends on a specific role, the revenue is nearly in hand and the math is different.
2. The role is a founder replacement in a function you're actively destroying. If you're the bottleneck and it's costing you deals, the runway math has to include the cost of you not fixing it.

What doesn't work: hiring "to grow into the revenue." That's how you end up with a team sized for a company you don't have yet. I made this mistake in 2021 with a marketing hire I couldn't afford, and it shortened my runway by four months for zero incremental revenue.

Takeaway: break the rule deliberately, with a written reason, and with a shorter review cycle.

The number that actually decides it

Runway math isn't about being conservative for its own sake. It's about buying yourself the ability to say no — to bad terms, to panicked cuts, to the bridge round that strips your equity. Every month of runway you protect before a hire is a month of optionality you keep after it.

So here's the next action: open a spreadsheet today and build the three-scenario model with your current numbers. Don't wait for a candidate to appear. Once the model exists, the hiring decision takes ten minutes instead of ten sleepless nights.

And when the trigger fires and the math holds, hire boldly — because a company that never hires never grows either.

Frequently Asked Questions

How many months of runway should I have before hiring?

Twelve months post-hire in your worst-case scenario is a reasonable floor for most startups. If you're pre-revenue or in a highly volatile market, aim for 15–18 months. Below 9 months post-hire, you're one bad quarter away from forced cuts.

Should I include future fundraising in my runway calculation?

No. Calculate runway on cash you have today, then treat the raise as a separate scenario. Including expected funding in your base runway is how founders end up hiring against money that never arrives or arrives on worse terms than planned.

What's the difference between gross burn and net burn?

Gross burn is total monthly spending. Net burn is spending minus revenue. For hiring decisions, use net burn — but only count revenue you can actually rely on, which usually means recurring or already-invoiced revenue, not pipeline.

How do I calculate the fully loaded cost of a new hire?

Start with gross salary, add 15–30% for employer taxes and contributions, add benefits ($400–$900/month), add software seats and equipment, and add any recruiting fee (15–25% of first-year salary). The total typically lands at 1.25x to 1.4x the salary figure.

Can I hire a contractor instead to protect runway?

Sometimes, yes. Contractors avoid benefits and long-term commitments, which helps in short-runway situations. But they cost more per month and can leave mid-project, so for anything beyond a 6-month horizon, a full-time hire usually delivers better cost per unit of output.