Startup & SaaS calculators
The unit-economics and fundraising toolkit for founders — customer acquisition cost, lifetime value, runway, burn rate, market sizing and post-money valuation.
CAC
Work out how much it costs to acquire one customer — blended, marketing and sales CAC.
LTV
Estimate a customer's lifetime value from order value, frequency and lifespan — or churn.
LTV:CAC Ratio
Compare lifetime value to acquisition cost and interpret the ratio.
CAC Payback Period
See how long it takes to recover CAC from a customer's gross profit.
Startup Runway
Estimate how many months of cash you have left, with scenarios and a chart.
Burn Rate
Calculate gross and net monthly burn, annualized burn and runway.
TAM
Estimate your total addressable market, top-down or bottom-up.
SAM
Estimate the serviceable share of your TAM you can realistically reach.
SOM
Estimate the obtainable share of your market, with a TAM→SAM→SOM funnel.
Post-Money Valuation
Work out post-money valuation, investor ownership and founder dilution.
Which startup calculator should you start with?
The answer depends on your current stage and the question you are trying to answer. If you are pre-revenue, start with Runway and Burn Rate — knowing exactly how many months of cash you have is the most important number for any early-stage founder. If you are raising a round, the Startup Valuation Calculator and Post-Money Valuation Calculator help you understand dilution and cap table impact before you negotiate.
For market sizing, the TAM, SAM, and SOM Calculators help you frame your pitch deck slide. For SaaS unit economics, track CAC, LTV, and CAC Payback Period together — investors will ask for all three.
The startup metrics investors actually look at
Burn rate and runway
Monthly burn = Total monthly expenses − Monthly revenue. Net burn is the cash leaving the business each month. Runway = Cash balance ÷ Monthly burn. Most investors want to see 12–18 months of runway before a funding round closes. If you have less than 6 months, fundraising should be your primary focus.
CAC and LTV
CAC = Total sales and marketing spend ÷ New customers acquired. Include salaries, ad spend, tools, and agency fees in the numerator. LTV = Average revenue per customer ÷ Churn rate (for subscription businesses). The LTV:CAC ratio should be 3:1 or higher for a sustainable SaaS business. Investors also look at CAC payback period — the months needed to recover the cost of acquiring a customer — and prefer this to be under 12 months for Series A candidates.
SaaS valuation multiples
Early-stage SaaS valuations are typically based on ARR multiples. As of 2025–2026, Series A SaaS companies growing 100%+ YoY can command 10–20× ARR; those growing 50–100% typically see 6–12×; below 50% growth, multiples compress to 3–6×. Profitability and net revenue retention (NRR) above 120% can push multiples higher.
TAM, SAM, SOM
TAM (Total Addressable Market) is the total revenue opportunity if you captured 100% of the market. SAM (Serviceable Addressable Market) is the portion your product can actually serve. SOM (Serviceable Obtainable Market) is what you can realistically capture in 3–5 years. Investors want credible SOM estimates — a $1B TAM with a realistic 2% SOM ($20M) is more convincing than hand-wavy “$50B market” claims.
Common founder mistakes with startup metrics
- Calculating CAC without including salaries. If your sales team costs $200K per year and acquires 50 customers, each customer costs $4,000 — even if your ad spend was zero. Most founders undercount CAC by 40–60%.
- Using gross churn instead of net revenue retention. Losing 10% of customers but expanding revenue from retained customers can result in positive NRR. Investors care more about NRR than raw churn for SaaS businesses.
- Building market size estimates top-down only. "We only need 1% of a $10B market" is the least convincing slide in any pitch deck. Build SAM and SOM from the bottom up: how many potential customers, at what price point, acquired through which channels.
- Conflating ARR with revenue. ARR (Annual Recurring Revenue) is a forward- looking metric: monthly recurring revenue × 12. It is not the same as trailing twelve months (TTM) revenue if you have significant non-recurring income or if MRR is growing fast.
Frequently asked questions
How much runway should a startup have before raising?
Most investors recommend starting a fundraise with 12–18 months of runway remaining. This gives you enough time to run a proper process (typically 3–6 months for seed to Series A) without negotiating from a position of desperation. Raise when you don't desperately need to.
What is a good CAC payback period for SaaS?
Under 12 months is considered strong for Series A SaaS. 12–18 months is acceptable. Above 24 months is a concern unless your LTV is very high and churn is very low. For enterprise SaaS with multi-year contracts, payback periods of 18–24 months are common and acceptable to investors.
How is a pre-revenue startup valued?
Pre-revenue valuations are largely negotiated based on team, market, traction (users, waitlist, pilots), and comparable deals. Common benchmarks: pre-seed rounds often value companies at $3M–$10M; seed rounds $5M–$20M. The Startup Valuation Calculator uses revenue and ARR multiples, which apply from the point you have recurring revenue.
What is post-money valuation?
Post-money valuation = pre-money valuation + investment amount. If investors value your company at $8M pre-money and invest $2M, the post-money valuation is $10M and the investors own 20% ($2M ÷ $10M). The Post-Money Valuation Calculator shows you exactly how dilution works for any deal structure.