Hissab

Strict, unit-aware calculator for units, dates, percentages, finance and developer math, with inline results and graphs. Hissab is a calculator you write in like a notepad. Put one calculation on each line, in plain words, and the answer appears on the right as you type.

5 km to miles → 3.1069 miles 20% of 150 → 30 3:30 pm pst in london → 11:30 pm london emi(360000, 6.5%, 30 years) → 2,275.4449 255 to hex → 0xff

What it can do

• Units: length, weight, volume, temperature, speed, area, data, energy, pressure and more, including compound units such as km per hour. If the units don't match, you get an error instead of a wrong answer.
• Dates and times: add durations to dates, measure the time between two dates, convert times across time zones, and turn Unix timestamps into readable dates.
• Percentages and money: percent of, discounts, sales tax, tips, loan EMIs, simple and compound interest, CAGR, NPV and IRR.
• Developer math: hex, binary and octal, bitwise operators, IPv4 and IPv6 addresses and subnets, colors, hashes (MD5, SHA-1, SHA-256, SHA-3, CRC32 and more), UUIDs and random IDs.
• Math and science: trigonometry, logarithms, statistics, combinatorics, complex numbers, matrices, symbolic algebra, and derivatives and integrals shown in proper math notation.
• Graphs: draw(sin(x), cos(x)) plots curves right under your calculations.

Works like a scratchpad

• Name a value once (price = 1299) and use it on any later line.
• Refer to earlier results with prev, or by line number (line3).
• Double-click a result to copy it.
• Click a color or a date to change it with a picker.
• Your sheet saves automatically and is waiting the next time you open the popup.