Calculators for people who build and run software

Free, fast, no sign-up. Each tool answers one question and shows its working. Nothing you type leaves your browser.

SaaS

SaaS Metrics Calculator

MRR, ARR, NRR/GRR, churn, ARPA, LTV, CAC, LTV:CAC, CAC payback and Quick Ratio from one screen of inputs.

Freelance

Freelance Hourly Rate Calculator

Turn a target take-home income into the hourly rate you need to charge — after unpaid time, business expenses and taxes.

Personal Finance

Subscription Cost Calculator

List your recurring subscriptions and see what they really cost per month, per year, and over five years.

DevOps

Uptime / SLA Calculator

Turn an SLA percentage like 99.9% into the exact downtime it allows per day, week, month and year — and work it backwards.

DevOps

Cost of Downtime Calculator

Estimate what an outage costs in lost revenue, lost productivity and recovery — as a total and per minute of downtime.

Personal Finance

Inflation Calculator

See what a US dollar amount from one year is worth in another, with cumulative and average annual inflation.

Personal Finance

Savings Goal Calculator

Work out how much to save each month to hit a goal by a date — or how long a fixed monthly amount will take.

Freelance

Hourly to Salary Calculator

Convert an hourly rate to yearly, monthly and weekly pay, and back again — with your own hours and weeks.

Personal Finance

Compound Interest Calculator

Project savings or investments over time with a starting amount, regular contributions and compounding — with a year-by-year breakdown.

DevOps

LLM API Cost Calculator

Estimate what an LLM feature costs per request, per day and per month from token volume and per-model pricing.

More tools coming

This site is being built out one calculator at a time — freelance rate, cloud cost comparison, LLM API cost, crypto staking and others are on the way.