Developer Utilities
Small developer utilities that save a trip to a random website. Encode and decode Base64, explain a regex, build UTM links, generate QR codes and vCards, and more — the everyday helpers. Free in your browser, and available by API when you need them in a script.
Developer Utilities
Base36 encoder
convert integer to or from base-36 (0-9 A-Z), free
POST /fmt/base36$0.002Developer Utilities
BCD converter
decimal ↔ 8421 binary-coded decimal, free
POST /fmt/bcd$0.002Developer Utilities
Binary to decimal converter
base-2 to base-10, free
POST /fmt/binary-decimal$0.002Developer Utilities
Decimal to hex converter
base-10 integer to base-16, free
POST /fmt/decimal-hex$0.002Developer Utilities
Engineering notation converter
SI prefixes, free
POST /fmt/engineering-notation$0.002Developer Utilities
Greek numeral converter
Ionic numerals with keraia, free
POST /fmt/greek-numerals$0.002Developer Utilities
Percent to fraction converter
reduced fraction from %, free
POST /fmt/percent-fraction$0.002Developer Utilities
Roman fraction converter
uncia notation from twelfths, free
POST /fmt/roman-fraction$0.002Developer Utilities
Significant figures rounder
round to N sig figs, free
POST /fmt/sig-figs$0.002Developer Utilities
Along-track distance calculator
great-circle projection, free
POST /geo/along-track-distance$0.002Developer Utilities
Compass direction to bearing
32-point name to degrees, free
POST /geo/compass-to-bearing$0.002Developer Utilities
Geohash decoder
latitude, longitude & cell error, free
POST /geo/geohash-decode$0.002Developer Utilities
Great-circle path intersection
two bearings meet, free
POST /geo/great-circle-intersection$0.002Developer Utilities
Magnetic to true bearing
declination conversion both ways, free
POST /geo/magnetic-true-bearing$0.002Developer Utilities
Geographic polygon area
spherical m² from lat/lon ring, free
POST /geo/polygon-area$0.002Developer Utilities
Rhumb line distance calculator
constant-bearing path, free
POST /geo/rhumb-distance$0.002Developer Utilities
Map tile to lat/lon
slippy XYZ north-west corner, free
POST /geo/tile-to-latlon$0.002Developer Utilities
UTM to lat/lon converter
zone, easting, northing to WGS84, free
POST /geo/utm-to-latlon$0.002Developer Utilities
Web Mercator projection calculator
lat/lon to EPSG:3857 X/Y meters, free
POST /geo/web-mercator-project$0.002Developer Utilities
Chord length calculator
from radius and angle or distance to center
POST /geom/chord-length$0.002Developer Utilities
Circle through three points
find center and radius from three coordinates
POST /geom/circle-from-3-points$0.002Developer Utilities
Cone volume calculator
volume, slant height, lateral and total surface
POST /geom/cone$0.002Developer Utilities
Dodecahedron calculator
volume and surface area from edge length
POST /geom/dodecahedron$0.002Developer Utilities
Ellipse calculator
area, Ramanujan perimeter, eccentricity, foci
POST /geom/ellipse$0.002Developer Utilities
Line intersection calculator
two lines in slope-intercept or standard
POST /geom/line-intersection$0.002Developer Utilities
Pipe volume calculator
internal and material volume from inner and outer
POST /geom/pipe-volume$0.002Developer Utilities
Polygon area calculator
shoelace formula from ordered vertices
POST /geom/polygon-area-shoelace$0.002Developer Utilities
Prism surface area calculator
lateral and total area from perimeter
POST /geom/prism-surface$0.002Developer Utilities
Pyramid volume calculator
volume, slant height and surface area
POST /geom/pyramid$0.002Developer Utilities
Rhombus calculator
area, perimeter, and side from diagonals or angle
POST /geom/rhombus$0.002Developer Utilities
Slope calculator
line slope and inclination angle from two points
POST /geom/slope$0.002Developer Utilities
Spherical segment calculator
volume and lateral zone area from radius
POST /geom/spherical-segment$0.002Developer Utilities
Square pyramid volume
slant height, lateral and total surface area
POST /geom/square-pyramid-solver$0.002Developer Utilities
Torus volume calculator
volume and surface area from tube and center
POST /geom/torus$0.002Developer Utilities
45-45-90 triangle calculator
legs, hypotenuse, and area from one side
POST /geom/triangle-45-45-90$0.002Developer Utilities
Circumcenter calculator
center and radius of a triangle's circumcircle
POST /geom/triangle-circumcenter$0.002Developer Utilities
SSA triangle calculator
ambiguous case, zero one or two solutions
POST /geom/triangle-ssa$0.002Developer Utilities
Calorie deficit calculator
daily intake from weight-loss goal, free
POST /health/calorie-deficit$0.002Developer Utilities
Cycling speed from power calculator
watts, weight, grade & CdA, free
POST /health/cycling-speed-power$0.002Developer Utilities
Body frame size calculator
small, medium or large from height &, free
POST /health/frame-size$0.002Developer Utilities
Lean body mass calculator
Boer formula from weight, height & sex, free
POST /health/lean-body-mass$0.002Developer Utilities
Maximum heart rate calculator
Fox, Tanaka, Gulati formulas free
POST /health/max-heart-rate$0.002Developer Utilities
Pace to speed converter
min/km or min/mi to km/h and mph, free
POST /health/pace-to-speed$0.002Developer Utilities
Pulse pressure calculator
systolic minus diastolic, free
POST /health/pulse-pressure$0.002Developer Utilities
Swimming calorie calculator
calories burned by duration, weight
POST /health/swimming-calories$0.002Developer Utilities
Rockport one-mile walk VO2 max calculator
free estimate
POST /health/vo2max-rockport$0.002Developer Utilities
Walking calorie calculator
calories burned from distance, pace, weight
POST /health/walking-calories$0.002Developer Utilities
Guitar capo key calculator
sounding key and chords from shapes and fret
POST /hobby/capo-key$0.002Developer Utilities
Crochet yarn estimator
length from dimensions, gauge and yardage
POST /hobby/crochet-yarn$0.002Developer Utilities
Dice probability calculator
exact P(sum) for n dice, free
POST /hobby/dice-probability$0.002Developer Utilities
Flash guide number calculator
aperture or distance from GN and ISO
POST /hobby/flash-guide-number$0.002Developer Utilities
Frequency to note calculator
nearest note, octave and cents from Hz
POST /hobby/frequency-to-note$0.002Developer Utilities
Hyperfocal distance calculator
H and near limit from f, N, CoC
POST /hobby/hyperfocal$0.002Developer Utilities
Line height calculator
px from font size and ratio, free
POST /hobby/line-height$0.002Developer Utilities
500 rule calculator
max shutter before star trails (focal × crop)
POST /hobby/rule-500$0.002Developer Utilities
Baseboard trim calculator
pieces from room perimeter and door, free
POST /home/baseboard$0.002Developer Utilities
Brick calculator
bricks needed from wall area, free
POST /home/bricks$0.002Developer Utilities
Drywall sheet calculator
sheets and screws from wall and ceiling, free
POST /home/drywall$0.002Developer Utilities
Fence picket calculator
pickets from length, width and gap, free
POST /home/fence-pickets$0.002Developer Utilities
Grass seed calculator
seed amount from lawn area and rate, free
POST /home/grass-seed$0.002