Calculators

Enter a resolution to get its simplified aspect ratio, or start from a ratio and one side to get the missing dimension. Knows the common ratios like 16:9, 4:3 and 21:9 and shows how close your size is to each.

Calculate AND, OR, XOR, NOT and bit shifts with a live binary view of every operand and the result. Enter numbers in decimal, hex, octal or binary and see each bit line up as you type.

Convert Unix file permissions between checkboxes, octal like 755 and symbolic notation like rwxr-xr-x, all kept in sync as you edit any of them. Covers setuid, setgid and the sticky bit, and shows the matching chmod command ready to copy.

Convert between px, rem, em, percent, pt and viewport units with a configurable root font size. Type into any field and the others update as you go, set the parent font size for em math, and read a conversion table for common sizes.

Work with dates: count the days between two dates, add or subtract a duration, get someone's exact age, and look up the ISO week number, day of year and other facts about any date.

Work out how long a download or file transfer takes from the file size and your connection speed. Handles all the common size and speed units, breaks the duration down readably, compares typical connections and can also solve for speed or file size.

See what a monthly ETF savings plan grows to after fund costs, inflation and tax. Also finds the contribution a target needs and how long withdrawals last.

Calculate an IPv4 or IPv6 subnet from an address and prefix or netmask: network, broadcast, usable hosts and masks, plus a binary view and subnet splitting.

Work out the monthly payment, total interest and payoff date of a loan or mortgage, find the loan you can afford from a payment, or how long a payment takes. See the full amortization schedule, the balance after a fixed-rate period and how extra payments shorten it.

Convert numbers between binary, octal, decimal, hexadecimal and any base up to 36. Type into any field and the others update as you go. Handles huge integers without losing precision and accepts 0x, 0b and 0o prefixes.

Answer any percentage question as you type: what is X% of a number, what percent one number is of another, the percentage increase or decrease between two values, a number raised or lowered by a percent, and the whole behind a part.

Convert between pixels and print size at any DPI. See how large an image prints in cm or inches, or how many pixels a print needs, A0 to A10 included.

Solve proportions with the rule of three: enter three values and the fourth is calculated as you type. Covers direct and inverse proportionality, shows the formula with your numbers plugged in, and explains the result in a sentence.

Convert between scientific notation and full numbers as you type. Reads 1.23e5, 1.23 × 10^5 and plain numbers, shows the value written out, in normalized scientific notation and in engineering notation, and can round to any number of significant digits.

Convert between common units of length, mass, temperature, area, volume, speed, pressure, energy, power, time, data, angle and frequency, from millimeters to light-years. Pick a unit, type a value and read the result with as many decimals as you want.

Enter a salary as an hourly, monthly or yearly figure and the rest fill in for you, including what you actually earn per second, minute, hour and working day. Set your currency and adjust your hours per day, days per week and weeks per year.

Compare options against the criteria that matter to you. Weight each criterion, score every option, and get a clear ranking with each option's score broken down, plus a check of how close the result is and what would change it.