45 free tools for founders
Work out pricing, runway, valuation and AI cost — in your browser, no signup, nothing saved. Plus AI tools for the spec and the code.
Just shipped Token Counter ·Startup Valuation Calculator ·SaaS Valuation Calculator ·Equity Dilution Calculator
Pricing & Margins
What should I charge, and what's left after costs?
Profit Margin Calculator
Reading a P&L: gross, operating and net margin from one set of numbers. For pricing a single item, use the markup calculator.
Markup Calculator
Pricing one item: fill any two of cost, price, markup, margin or profit and the rest follow.
Freelance Rate Calculator
The hourly and day rate that actually reaches your target income once unbillable hours, expenses and tax have taken their share.
SaaS Pricing Calculator
Model two pricing scenarios side by side across your tiers — including the customers a price rise costs you, which single-scenario calculators have to ignore.
Cash & Runway
How long does the money last at this burn?
IRR Calculator
Internal rate of return on an uneven cash flow series, with MIRR beside it and a warning when the series has more than one valid IRR.
NPV Calculator
Net present value on an uneven cash flow series, with the outlay-timing convention made explicit and the discount rate at which the answer flips.
Break-Even Calculator
Units and revenue needed to cover fixed costs, with revenue and total cost charted so the crossover is visible rather than just stated.
EBITDA Calculator
EBITDA and EBITDA margin from your P&L, calculated two ways so the numbers cross-check each other.
Payback Period Calculator
When an investment earns itself back — simple and discounted, with even or uneven cash flows and the cumulative curve charted.
Burn Rate Calculator
Gross burn, net burn and runway — modelled with revenue growing, not held flat, because that is where the plain division goes wrong.
Growth & Customers
Is the business growing, or quietly leaking?
CAGR Calculator
Compound annual growth rate between two values, solved in any direction — rate, ending value, starting value or number of years.
Customer Lifetime Value Calculator
LTV with the gross margin term most people leave out, next to the revenue-only figure it inflates — plus LTV:CAC and CAC payback.
Net Promoter Score Calculator
Promoters minus detractors, with the 95% confidence interval around it — because on a few hundred responses most quarterly NPS movement is noise.
Customer Acquisition Cost Calculator
CAC read three ways at once — paid-only, fully loaded and blended — because which one you quote changes the answer by more than the arithmetic does.
Annual Recurring Revenue Calculator
ARR from monthly, annual and multi-year contracts, with the one-off fees and services entered separately so you can watch them not count.
Revenue Growth Calculator
Paste a revenue series and get the latest period, the compound rate across the whole range, and what that annualises to — with the best and worst months a single rate hides.
Churn Rate Calculator
Customer, revenue and net revenue churn from one set of numbers — because they can point in opposite directions, and which one you quote changes the story.
Rule of 40 Calculator
Growth plus EBITDA margin against the 40 threshold — with the composition alongside it, because two businesses can score the same and be worth very different multiples.
Unit Economics Calculator
LTV, CAC payback and LTV:CAC for one subscription customer — plus which of the four levers actually closes the gap when the ratio is short.
Fundraising & Equity
What's it worth, and who ends up owning what?
DCF Calculator
Discounted cash flow valuation with the terminal value shown as a share of the total, and a sensitivity grid across both assumptions that actually drive it.
Startup Valuation Calculator
Berkus, Scorecard and the VC method run side by side on a pre-revenue company — and the spread between them, which is the honest answer.
NewEquity Dilution Calculator
Founder ownership through every funding round, including the option pool shuffle — the pre-money carve-out founders pay for entirely and investors do not.
NewSaaS Valuation Calculator
What a SaaS business is worth as a range rather than a figure, with the drivers behind the multiple and the method a buyer at your size would actually use.
NewTAM SAM SOM Calculator
The three market tiers built top-down and bottom-up at the same time, because the gap between the two methods is the only real signal in the exercise.
Co-Founder Equity Split Calculator
Frank Demmler’s Founders’ Pie method, with capital contribution added — weight what matters to your company, rate each founder, and get a split to argue about.
Startup Stock Option Calculator
What an option grant is worth at several exit valuations — with dilution applied, which is the assumption most equity calculators quietly skip.
Product & Planning
What should we build, and how do we write it down?
Code & Shipping
How do we ship it without breaking things?
JSON Formatter
Formats, minifies and checks JSON in your browser without going through JSON.parse — so duplicate keys and oversized numbers survive to be reported.
Base64 Encoder & Decoder
Two-way base64 that handles UTF-8, accepts the URL-safe alphabet, and tells you what is wrong with a string instead of returning garbage.
Unix Timestamp Converter
Epoch to date and back, with the unit detected rather than assumed — plus ISO 8601, RFC 2822 and Discord markup.
UUID Generator
v4 and v7 UUIDs from the browser CSPRNG, in bulk, with the formatting options you would otherwise apply by hand.
XML Formatter & Validator
Formats and validates XML in your browser, points at the exact line of every error, and refuses to reindent whitespace that is actually data.
JWT Decoder
Decodes a JWT in your browser and answers the question you opened it for — expired, exploitable header, or personal data sitting readable in the payload.
SQL Query Formatter
Formats to 16 dialects in your browser, proves only whitespace changed, and flags the missing WHERE before you run it.
Compare JSON
Compares two JSON documents by value, not by text — so reordered keys and reordered array items stop counting as changes.
SSL Certificate Decoder
Decodes X.509 certificates and CSRs in your browser, and checks whether a pasted chain actually joins up.
HAR Analyzer
Reads a HAR file in your browser and starts with the credentials recorded inside it, then does the performance analysis.
Hash Generator
MD5, SHA-1, SHA-256, SHA-384 and SHA-512 of the same input at once, plus a compare box that names which algorithm a pasted hash came from.
Uptime Calculator
What an SLA percentage buys you in real downtime — per day, week, month, quarter and year — and the reverse after an incident.
Slug Generator
Titles to URL slugs with the transliteration done properly — München becomes munchen, not mnchen — plus batch mode with duplicate detection.
Code Explainer
Paste code you did not write and get it explained line by line, with the parts that will bite you called out separately.
AI Cost & ROI
What will the AI actually cost to run?
Token Counter
Exact token counts from the real BPE encodings, next to what the four-characters-per-token rule would have predicted — and it is wrong in both directions.
NewAI ROI Calculator
What AI tooling actually returns once adoption, ramp-up and setup cost are in the model — the three things vendor calculators leave out.
Team & Delivery
Can the team deliver it, and by when?
Meeting Cost Calculator
What a meeting costs in fully-loaded salary, and what it costs across a year if it recurs — with a live ticker and a line you can paste into Slack.
Story Points Calculator
A consistent rubric for the three things story points actually measure, mapped onto the Fibonacci scale — and a points-to-time conversion that goes through velocity rather than a made-up hourly rate.
Nothing matches that. Try “margin”, “runway” or “PRD”.
Want a real spec for what you’re building?
Drop a sentence. Tekk grounds it in your actual code and turns it into an executable plan.
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