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
Tip options comparison calculator
gratuity amounts by percent
POST /finance/tip-options$0.002Developer Utilities
True hourly wage calculator
commute and expenses adjusted
POST /finance/true-hourly-wage$0.002Developer Utilities
Airy disk diameter calculator
diffraction blur (λ, f-number)
POST /hobby/photo-airy-disk$0.002Developer Utilities
Cropped image resolution
remaining pixels and megapixels
POST /hobby/photo-crop-resolution$0.002Developer Utilities
Full-frame equivalent focal length calculator
POST /hobby/photo-equivalent-focal-length$0.002Developer Utilities
Extension Tube Magnification Calculator for Close-Up Photography
POST /hobby/photo-extension-tube-magnification$0.002Developer Utilities
Focus stacking frame count calculator
DOF, depth & overlap
POST /hobby/photo-focus-stack-frames$0.002Developer Utilities
Horizontal angle of view calculator
focal length and sensor width
POST /hobby/photo-horizontal-angle-of-view$0.002Developer Utilities
ND filter shutter speed calculator
new time after stops
POST /hobby/photo-nd-filter-shutter$0.002Developer Utilities
Stacked ND Filters Total Stops Calculator
POST /hobby/photo-nd-filter-stack$0.002Developer Utilities
Time-lapse Shooting Duration Calculator
POST /hobby/photo-timelapse-shoot-duration$0.002Developer Utilities
Depth of field from magnification
macro DOF calculator
POST /hobby/photo-dof-from-magnification$0.002Developer Utilities
Flash inverse square falloff calculator
distance change in stops
POST /hobby/photo-flash-inverse-square$0.002Developer Utilities
Looney 11 lunar exposure calculator
moon aperture from ISO & shutter
POST /hobby/photo-looney11-moon$0.002Developer Utilities
Moon diameter in pixels calculator
plan lunar image scale
POST /hobby/photo-moon-pixel-size$0.002Developer Utilities
Shutter Speed After Stops Change Calculator
POST /hobby/photo-shutter-after-stops$0.002Developer Utilities
Stops between two apertures calculator
compare f-numbers
POST /hobby/photo-stops-between-apertures$0.002Developer Utilities
Video bitrate for memory card
max Mbps for your recording length
POST /hobby/photo-video-bitrate-for-card$0.002Developer Utilities
Bar duration from time signature calculator
measure length in seconds
POST /hobby/music-bar-duration$0.002Developer Utilities
BPM from tap intervals calculator
tempo from tap timestamps, free
POST /hobby/music-bpm-from-tap$0.002Developer Utilities
Cents to frequency ratio calculator
convert pitch intervals
POST /hobby/music-cents-to-ratio$0.002Developer Utilities
Delay time from BPM calculator
straight, dotted & triplet echoes
POST /hobby/music-delay-time$0.002Developer Utilities
Reverb decay time from BPM calculator
tempo-synced ms, free
POST /hobby/music-reverb-decay$0.002Developer Utilities
MIDI ticks per note value calculator
PPQ resolution to tick lengths
POST /hobby/music-ticks-per-note$0.002Developer Utilities
Slow-motion playback duration calculator
POST /hobby/photo-slowmo-playback$0.002Developer Utilities
Star trail stacking calculator
how many frames for continuous trails
POST /hobby/photo-star-trail-count$0.002Developer Utilities
Cents to pitch-bend value calculator
MIDI bend from cents, free
POST /hobby/music-cents-to-pitch-bend$0.002Developer Utilities
Chord inversion notes calculator
root position and every inversion
POST /hobby/music-chord-inversion$0.002Developer Utilities
Interval between two notes calculator
quality and number
POST /hobby/music-interval-between-notes$0.002Developer Utilities
Key from sharps or flats count
major and minor key signature calculator
POST /hobby/music-key-from-accidentals$0.002Developer Utilities
Relative major key calculator
find the major key for any minor key
POST /hobby/music-relative-major$0.002Developer Utilities
Transpose key by interval calculator
roots and qualities
POST /hobby/music-transpose-key$0.002Developer Utilities
Expected highest die calculator
exact keep-highest average
POST /hobby/game-dice-expected-highest$0.002Developer Utilities
Probability dice sum at most calculator
exact cumulative odds
POST /hobby/game-dice-sum-at-most$0.002Developer Utilities
Distance between adjacent frets calculator
scale length spacing
POST /hobby/music-fret-spacing$0.002Developer Utilities
Organ pipe diameter scale calculator
length, halving ratio & Normalmensur
POST /hobby/music-organ-pipe-diameter$0.002Developer Utilities
PCM Audio Bitrate Calculator
Raw Data Rate
POST /hobby/music-pcm-bitrate$0.002Developer Utilities
Polyrhythm Alignment Calculator
Find the Common Pulse Grid
POST /hobby/music-polyrhythm-alignment$0.002Developer Utilities
Pythagorean tuning interval ratio calculator
stack pure fifths
POST /hobby/music-pythagorean-ratio$0.002Developer Utilities
Tuning error in cents calculator
pitch deviation for fine tuning
POST /hobby/music-tuning-error-cents$0.002Developer Utilities
Chess material balance calculator
compare both sides
POST /hobby/chess-material-balance$0.002Developer Utilities
D&D Encumbrance Threshold Calculator by Strength
POST /hobby/dnd-encumbrance$0.002Developer Utilities
D&D initiative modifier calculator
dex, feats & items
POST /hobby/dnd-initiative-modifier$0.002Developer Utilities
D&D point buy cost calculator
5e ability score total
POST /hobby/dnd-point-buy$0.002Developer Utilities
D&D spell attack bonus calculator
proficiency plus ability modifier
POST /hobby/dnd-spell-attack-bonus$0.002Developer Utilities
D&D XP to Next Level Calculator
POST /hobby/dnd-xp-to-next-level$0.002Developer Utilities
d20 success chance vs DC calculator
P(d20 + mod ≥ DC), free
POST /hobby/game-d20-success$0.002Developer Utilities
Dice notation min and max calculator
range for NdS rolls, free
POST /hobby/game-dice-notation-range$0.002Developer Utilities
Chess performance rating calculator
tournament PR from field & score %
POST /hobby/chess-performance-rating$0.002Developer Utilities
Knitting stitches for width calculator
use your swatch gauge
POST /hobby/craft-knit-stitches-for-width$0.002Developer Utilities
D&D challenge rating to XP calculator
5e CR to experience points
POST /hobby/dnd-cr-to-xp$0.002Developer Utilities
Bingo card combinations calculator
how many distinct cards
POST /hobby/game-bingo-combinations$0.002Developer Utilities
Go Area Score Calculator
Territory, Stones and Komi
POST /hobby/game-go-area-score$0.002Developer Utilities
MTG mana curve calculator
average mana value and curve summary, free
POST /hobby/game-mtg-mana-curve$0.002Developer Utilities
Scrabble bingo bonus calculator
7-tile play + 50 points, free
POST /hobby/game-scrabble-bingo$0.002Developer Utilities
Sudoku Grid Validity Checker
Find Row, Column and Box Conflicts
POST /hobby/game-sudoku-validity$0.002Developer Utilities
Poker starting hand combinations calculator
exact preflop combos
POST /hobby/poker-hand-combinations$0.002Developer Utilities
Poker Pot Odds Calculator
Ratio and Call Percentage
POST /hobby/poker-pot-odds$0.002Developer Utilities
Beading Strand Length Calculator
Beads and Spacers
POST /hobby/craft-bead-strand-length$0.002Developer Utilities
Crochet Flat Circle Rounds Calculator
Stitch Increases
POST /hobby/craft-crochet-circle-rounds$0.002