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
Julian ↔ Gregorian converter
free
POST /date/julian-calendar$0.002Developer Utilities
Leap seconds UTC↔TAI
free
POST /date/leap-seconds$0.002Developer Utilities
NTP ↔ Unix timestamp
free
POST /date/ntp-timestamp$0.002Developer Utilities
Parse relative dates
free
POST /date/relative-parse$0.002Developer Utilities
Roman Kalends/Nones/Ides
free
POST /date/roman-date$0.002Developer Utilities
UUID v1/v6/v7 to timestamp
free
POST /date/uuid-time$0.002Developer Utilities
Weekday occurrence in month
free
POST /date/weekday-occurrence$0.002Developer Utilities
Sphere calculator
volume and surface free in your browser
POST /dev/sphere$0.002Developer Utilities
Voltage divider calculator
free in your browser
POST /dev/voltage-divider$0.002Developer Utilities
Polygon apothem calculator
free
POST /math/polygon-apothem$0.002Developer Utilities
Taxable equivalent yield calculator
free online
POST /finance/taxable-equivalent-yield$0.002Developer Utilities
Abjad numeral converter free online
POST /math/abjad-numerals$0.002Developer Utilities
Age ratio calculator
present and future ages free
POST /math/age-ratio$0.002Developer Utilities
Boat and stream speed calculator free online
POST /math/boat-stream$0.002Developer Utilities
CP SP MP calculator
cost selling marked price free
POST /math/cp-sp-mp$0.002Developer Utilities
Hebrew numeral converter and gematria free
POST /math/hebrew-numerals$0.002Developer Utilities
Largest remainder seat allocation free
POST /math/largest-remainder$0.002Developer Utilities
Maya vigesimal numeral converter free
POST /math/maya-numerals$0.002Developer Utilities
Pie chart angles from values free online
POST /math/pie-chart-angles$0.002Developer Utilities
Pipes and cisterns calculator free online
POST /math/pipes-cisterns$0.002Developer Utilities
Sainte-Laguë seat allocation calculator free
POST /math/sainte-lague$0.002Developer Utilities
Orthodox Christmas date
free
POST /date/orthodox-christmas$0.002Developer Utilities
Victoria Day (Canada) date
free
POST /date/victoria-day-ca$0.002Developer Utilities
Week of month calculator
free
POST /date/week-of-month$0.002Developer Utilities
CD early withdrawal penalty
free
POST /finance/cd-early-penalty$0.002Developer Utilities
Lease buyout cost
free
POST /finance/lease-buyout-cost$0.002Developer Utilities
Mortgage offset account savings
free
POST /finance/mortgage-offset$0.002Developer Utilities
Negative equity roll-in
free
POST /finance/negative-equity-rollin$0.002Developer Utilities
Mortgage points break-even
free
POST /finance/points-breakeven$0.002Developer Utilities
Prepayment penalty calculator
free
POST /finance/prepayment-penalty$0.002Developer Utilities
Quarterly estimated tax
free
POST /finance/quarterly-estimated-tax$0.002Developer Utilities
Standard vs itemized deduction
free
POST /finance/standard-vs-itemized$0.002Developer Utilities
Gall–Peters projection calculator
free
POST /geo/gall-peters$0.002Developer Utilities
Geocentric radius calculator
free
POST /geo/geocentric-radius$0.002Developer Utilities
Vertical sextant angle distance
free
POST /geo/vertical-sextant-angle$0.002Developer Utilities
Arithmetico-geometric series sum
free
POST /math/arithmetico-geometric-series$0.002Developer Utilities
Chain discount / net price factor
free
POST /math/chain-discount$0.002Developer Utilities
Hexagonal prism calculator
free
POST /math/hexagonal-prism$0.002Developer Utilities
Markdown percentage calculator
free
POST /math/markdown-percent$0.002Developer Utilities
Motzkin number calculator
free
POST /math/motzkin-number$0.002Developer Utilities
Power of a point calculator
free
POST /math/power-of-a-point$0.002Developer Utilities
Regular tetrahedron calculator
free
POST /math/regular-tetrahedron$0.002Developer Utilities
Roman chronogram calculator
free
POST /math/roman-chronogram$0.002Developer Utilities
Square pyramid calculator
free
POST /math/square-pyramid$0.002Developer Utilities
Stair rise and run calculator
free
POST /math/stairs-rise-run$0.002Developer Utilities
Tangent-secant theorem calculator
free
POST /math/tangent-secant-theorem$0.002Developer Utilities
Wastage allowance calculator
free
POST /math/wastage-allowance$0.002Developer Utilities
Hedges g effect size
free
POST /stat/hedges-g$0.002Developer Utilities
Matthews correlation (MCC)
free
POST /stat/matthews-corr$0.002Developer Utilities
Haversine distance - great-circle km, mi and m between two points
POST /geo/haversine$0.002Developer Utilities
Absolute value equation solver
solve |ax+b|=c for x
POST /algebra/absolute-value-equation$0.002Developer Utilities
Finite series partial sum
accumulate terms, free
POST /algebra/partial-sum-series$0.002Developer Utilities
2×2 system by substitution
isolate, solve, free
POST /algebra/system-2x2-substitution$0.002Developer Utilities
Kepler's third law calculator
find period or radius from a known orbit
POST /astro/kepler-third-law$0.002Developer Utilities
Physical size from angular diameter
small-angle calculator
POST /astro/physical-size-from-angular$0.002Developer Utilities
Propellant mass fraction calculator
delta-v and exhaust velocity
POST /astro/propellant-mass-fraction$0.002Developer Utilities
Limiting reactant calculator
which reactant runs out first
POST /chem/limiting-reactant$0.002Developer Utilities
Moles of product calculator
reactant moles and mole ratio
POST /chem/moles-of-product$0.002Developer Utilities
Electrolysis overpotential calculator
applied vs thermodynamic voltage
POST /chem/overpotential$0.002Developer Utilities
Percent yield calculator
actual over theoretical yield
POST /chem/percent-yield$0.002