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Startup Calculators
A startup calculator works out your runway, equity dilution or SAFE conversion, so founders raise and spend with clear numbers.
A startup calculator is a free tool that turns fundraising and spend into a number: months of runway, the equity a round dilutes, or how a SAFE note converts into shares. Startups live and die by cash and cap-table maths, so getting these right matters.
This hub gathers our startup finance tools in one place. Use the runway tool to plan cash, and the dilution and SAFE tools to model a raise. For broader money tools, see the finance hub.
All Startup Calculators
This page links four startup calculators. Each card opens one tool.
Which Startup Calculator Do I Need?
Match your goal to a tool in the table below. Each row names one task and the calculator that handles it.
| If You Want To... | Use This Calculator |
|---|---|
| See how long your cash lasts | Startup Runway Calculator |
| Model the equity a round dilutes | Dilution Calculator |
| Account for an option pool | Option Pool Dilution Calculator |
| Convert a SAFE into shares | SAFE Note Dilution Calculator |
What Are the Main Types of Startup Calculation?
Startup calculations split into two kinds on this page. Each answers a different question.
Cash and Runway
Runway tools show how long your cash lasts at the current burn rate.
Equity and Dilution
Dilution tools model how funding, option pools and SAFE notes split ownership.
How Is Startup Runway Calculated?
Startup runway is calculated as cash in the bank divided by monthly net burn. It shows how many months you can operate before you run out of money.
Dilution tools use a different method: they divide new shares by the total after a round to find the ownership each party keeps. Each tool shows its inputs.
How to Extend Your Runway
Runway is not fixed; you can extend it from either side. On the cost side, trim non-essential spending, delay new hires and renegotiate contracts to lower your monthly burn. On the revenue side, even small recurring income pushes the zero-cash date further out and can turn a fundraise from urgent to optional.
A common target is 18 to 24 months of runway after a raise, which gives enough time to hit the milestones the next round will be priced on. Recalculate whenever burn or revenue changes, so you always know how many months you truly have, not how many you had last quarter.
Startup Finance Concepts Compared
| Concept | What it is | Why it matters |
|---|---|---|
| Burn rate | Net cash you spend each month | Sets how fast your runway shrinks |
| Runway | Months of cash left at the current burn | Tells you when to raise or cut costs |
| Dilution | The drop in your ownership percent when new shares are issued | Shows what a round really costs founders |
| Option pool | Shares reserved for employees | Dilutes founders before the round, not investors |
| SAFE note | An agreement that converts to equity later | Delays pricing but still dilutes at conversion |
These figures are linked. A higher burn rate shortens runway, which pushes you to raise sooner, and each raise dilutes ownership, often more once the option pool is added before the round. Modeling them together, rather than one at a time, is what keeps founders in control of the cap table.
What Do the Key Startup Terms Mean?
Six terms decide how a raise affects a startup. Each definition below states the term in one line.
- Runway
- Runway is the number of months your cash lasts at the current burn rate.
- Burn Rate
- Burn rate is how much cash a startup spends net each month.
- Dilution
- Dilution is the drop in existing owners’ percentage when new shares are issued.
- Pre-Money Valuation
- Pre-money valuation is a company’s value before new investment is added.
- Option Pool
- An option pool is shares set aside for employees, which dilutes founders and investors.
- SAFE Note
- A SAFE note is an agreement that converts into equity at a later priced round.
Frequently Asked Questions
What is burn rate?
Burn rate is the net amount of cash your startup spends each month. Gross burn is total spending; net burn subtracts any revenue. It sets how fast your runway shrinks and how soon you must raise.
How much equity should I give investors?
Early rounds commonly sell 10 to 25 percent of the company, depending on how much you raise and your valuation. Give away only what the round requires, since every percent is harder to win back later.
What is a SAFE note?
A SAFE, or Simple Agreement for Future Equity, lets an investor fund you now in exchange for shares later, usually at the next priced round. It is fast and cheap but still dilutes your ownership when it converts.
How Do I Calculate Startup Runway?
Divide your cash in the bank by your monthly net burn. The runway calculator shows the months and the date you run out.
What Is Dilution in a Funding Round?
Dilution is the fall in existing owners’ percentage when new shares are issued. The dilution calculator shows how much each round costs founders.
How Does a SAFE Note Convert?
A SAFE converts into shares at the next priced round, using a valuation cap or discount. The SAFE note calculator models the conversion.
Do These Calculators Store My Figures?
No. Each calculator runs in your browser, and nothing is sent anywhere unless you save a result, which stays on your device.
Sources: Investopedia on dilution, and Y Combinator on SAFE notes.
Author
Shakeel Muzaffar is the Founder and Editor-in-Chief of MultiCalculators.com, bringing over 15 years of experience in digital publishing, product strategy, and online tool development. He leads the platform's editorial vision, ensuring every calculator meets strict standards for accuracy, usability, and real-world value. Shakeel personally oversees content quality, formula verification workflows, and the platform's commitment to publishing tools that are genuinely useful for students, professionals, and everyday users worldwide.
