Small tools that get one thing done.
Fifteen calculators, converters and generators for the tasks you do a few times a week. Everything runs in your browser — no install, no account, no uploads.
All 15 tools
TipSplit
Split a bill between up to 20 people, choose a tip, round up, and screenshot the receipt.
LivePercent Calculator
X% of a number, what percent one number is of another, and percent change — three answers in one screen.
LiveUnit Converter
Length, weight, volume and temperature. Type a value once and read every unit at the same time.
LiveDate Calculator
Days between two dates, or the date N days from now. Weekdays and month lengths handled.
LiveLoan Calculator
Monthly payment, total interest and the full payoff figure for any fixed-rate loan.
LiveAge Calculator
Exact age in years, months and days, total days lived, and a countdown to your next birthday.
LiveBMI Calculator
Body mass index in metric or imperial, the range it lands in, and the healthy weight band for your height.
LiveDiscount Calculator
Final price after a percent off, money saved, or the real discount when you only know the sale price.
LiveWord Counter
Words, characters, sentences and paragraphs, plus reading and speaking time. Nothing leaves your browser.
LivePassword Generator
Cryptographically random passwords with a live entropy readout. Generated locally, never stored.
LiveSalary Converter
Hourly pay to a yearly salary, or a salary back to an hourly rate. Monthly, weekly and daily figures included.
LiveCompound Interest
What a starting amount plus monthly contributions turns into over time, with the interest split out.
LiveTime Zone Converter
Compare a time across cities, including the day change and daylight saving.
LiveCase Converter
UPPERCASE, Title Case, camelCase, snake_case — seven styles, one click each.
LiveQR Code Generator
Turn a link into a QR code on your own device. Nothing uploaded, and the code never expires.
Pricing
- Lifetime access — pay once, use forever
- Every tool on this site, fully unlocked
- Every tool added later, included free
- No subscription, no renewal, no ads
- Works on phone, tablet and desktop
Early birdUse code EARLY40 at checkout for 40% off — $17.40 instead of $29. First 50 buyers.
Get All-Access — $29Instant delivery by email · 30-day refund policy
Runs on your device
Your numbers and text are processed in the browser. Nothing is sent to a server to get a result.
No account
Open the page and use it. There is nothing to sign up for, and nothing to verify by email.
Fast pages, no clutter
Each tool is a single lightweight page. No pop-ups, no countdowns, no newsletter wall.
More tools every week
Fifteen tools are live today and more are added every week. If there is a small task you do repeatedly and hate doing, tell us — support@koumen.net. The most requested ones get built first.
Get All-Access — $29