Developers do a lot of back-of-the-envelope math: what a pricing tier costs at next quarter’s traffic, how much disk a feature adds, what 99.9% uptime allows. This calculator for developers lets you write it the way you would write pseudocode, with named values and units, and see the answer on each line instead of opening a REPL.
Each example shows what Notes Calculator answers. Choose Open in Notes Calculator under any of them to open it in the web app.
API cost at your traffic
Price per thousand requests is the usual unit. Name the traffic and the price, and the monthly bill follows.
| Note | Result |
|---|---|
| requests per day = 50k | 50,000 |
| price per 1k = 0.02 USD | $0.02 |
| daily cost = requests per day / 1000 * price per 1k | $1 |
| Per 30-day month: daily cost * 30 | $30 |
Storage across users
Multiply the user count by the average data per user and convert to the unit your provider bills in.
| Note | Result |
|---|---|
| users = 100k | 100,000 |
| users * 50 MB to TB | 5 TB |
Hex and binary
Convert a value between bases on one line each.
| Note | Result |
|---|---|
| 255 to hex | FF ₁₆ |
| 0xFF to binary | 11111111 ₂ |
An SLA downtime budget
99.9% uptime leaves 0.1% of the period for downtime. Multiply the period by that share and convert it to minutes.
| Note | Result |
|---|---|
| 30 days * 0.1% to minutes | 43.20 minutes |
| 365 days * 0.1% to hours | 8.76 hours |
For number bases in more depth, see the hex, binary and octal guide, and for storage units, the byte converter guide. If you are choosing between notepad calculators, the comparisons cover Soulver, Numi and Parsify.
Start free at app.notescalculator.com, or see what Lifetime adds if you want unlimited notes synced across your machines.