Build a quote with named values
Use readable names with spaces, then change one value and let the whole note recalculate.
| Note | Result |
|---|---|
| hours = 12 | 12 |
| hourly rate = 50 | 50 |
| design fee = 80 | 80 |
| hours * hourly rate + design fee | 680 |
Variables · Percentages · Live currencies
A notepad that calculates as you type.
Build quotes and budgets with variables, percentages and live currencies. Change one input; the answers update.
One free note. Unlimited calculations. Lifetime adds unlimited notes and sync.
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- Windows
- Linux
- Android
- iOS
- Web
See it calculate
See what you can calculate
From a quick percentage to a reusable project note, the working and the answer stay side by side.
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Write percentages naturally
Calculate a share, add tax, or take a discount in the same words you would say aloud.
Quick calculations Note Result 10% of 200 20 20% of 150 30 200 + 15% 230 10% off 200 180 -
Write words and numbers together
Jot amounts the way you would say them, with the words right next to the numbers, then add them up.
Words and numbers Note Result $10 for lunch + 15% tip $11.50 $45 groceries $45 $12 taxi home $12 total $68.50 -
Convert units in place
Keep the question and its converted result together, including angles and areas.
Unit conversions Note Result 60 degrees in rad 1.05 rad 10 square km in square mile 3.86 mi² 1 cm + 100 mm 11 cm 10 W in kW 0.01 kW -
Check live currencies
Convert dollars, euros and Bitcoin directly in the note, then keep working with the answers.
Currency conversion Note Result $100 in euro €89 100 EUR in USD $112.36 0.01 BTC in USD $810 Illustrative rates: $1 = €0.89, 1 BTC = $81,000. The app uses live exchange rates. -
Plan with dates and durations
Measure date gaps, move deadlines, and add durations without leaving the note.
Dates and durations Note Result 12/25/2026 - 12/01/2026 3 weeks 3 days 12/25/2026 + 7 days 01/01/2027 1 hour + 30 minutes 1 hour 30 min -
Work across scales
Move between data, energy, and other measurement scales without looking up factors.
Scale conversions Note Result 2 GB in MB 2,000 MB 3 kcal in cal 3,000 cal 10k dyne in N 0.10 N -
Switch number bases
Convert and calculate with hexadecimal, binary, octal, and decimal values.
Programmer math Note Result 255 in hex FF 255 in binary 11111111 0xFF + 0x10 271 0b11010 in decimal 26
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One note is free. Write unlimited calculations in it. Lifetime (from €39.99 one-time, price in your currency at checkout) adds unlimited notes, with sync across signed-in devices.
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Use it where you work. Native apps for macOS, Windows, Linux, Android, and iOS, plus the web app.
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200+ live currencies. Rates refresh every hour. Keyboard shortcuts and dark and light themes keep daily work comfortable.
How it works
From blank page to answer in seconds
No formulas. No cells. No menus. Just write and let the calculator keep up with you.
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Open a fresh note
Launch Notes Calculator on any device. No accounts, no setup: just a blinking cursor.
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Type math like you would write it
Mix words, numbers, units, and currencies. Use variables to name values and reference them anywhere.
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Get answers as you type
Results appear instantly on the right. Reference variables, change one number, and watch totals update in real time.
Built for the way you work
One calculator. Every kind of math.
From freelance quotes to student homework, Notes Calculator adapts to whatever you're working on.
Freelancers
Turn hour estimates into fixed prices, total tracked time, and set tax aside.
ExploreStudents
Work through homework with variables, weighted grades, and unit conversions.
ExploreTravelers
Track the trip budget per day, split bills, and convert currencies and units on the road.
ExploreDevelopers
Estimate API costs and storage, convert hex and binary, and size SLA downtime.
ExploreEngineers
Keep units through stress, power, and expansion checks, with pi and SI shorthand built in.
ExploreSmall businesses
Price from cost, check the margin you keep, and take VAT out of a gross amount.
ExploreEveryday math
Tips, splits, percentages, and quick mental-math shortcuts: all in one place.
ExploreSee every audience: contractors, caterers, investors and more
From the blog
Calculator guides & deep dives
Workshop Quote Calculator: A Free Copyable Template
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Read articleComments, Labels, and Exporting Your Notes
Annotate Notes Calculator math with comments, labels and inline notes the parser ignores, nest conditionals in expressions, and export to Markdown, CSV or PDF.
Read articleBig Numbers: Type Millions to Nonillions Without the Zeros
Big numbers like 1,000,000,000,000 or a pasted 1.000.000.000.000.000 are hard to read. Type 1M to 1Q in Notes Calculator and calculate without counting zeros.
Read articleStop fighting your calculator.
Notes Calculator is free to use, fast to learn, and ready in your browser. Upgrade later if you want sync and unlimited notes.
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