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
Linear thermal expansion calculator
ΔL = L₀·α·ΔT from length, coefficient and temperature change, free
POST /thermo/linear-expansion$0.002Developer Utilities
Newton's law of cooling calculator
T(t) from Ta, T0, k, t, free
POST /thermo/newton-cooling$0.002Developer Utilities
Pressure calculator
P=F/A in Pa, bar and psi, free
POST /thermo/pressure-force-area$0.002Developer Utilities
Relative humidity calculator
RH from actual and saturation vapor pressure, free
POST /thermo/relative-humidity$0.002Developer Utilities
Reynolds number calculator
Re=ρVL/μ, free
POST /thermo/reynolds-number$0.002Developer Utilities
Specific heat capacity calculator
c = Q/(m·ΔT) from heat, mass and temperature change, free
POST /thermo/specific-heat-capacity$0.002Developer Utilities
Heat conduction calculator
Q = k A ΔT / L through a wall, free
POST /thermo/thermal-conduction$0.002Developer Utilities
Thermal efficiency calculator
η = (W/Q_in)×100% from work output and heat input, free
POST /thermo/thermal-efficiency$0.002Developer Utilities
Arrival local time calculator
flight duration + UTC offsets, free
POST /travel/arrival-local-time$0.002Developer Utilities
Average speed calculator
total distance over elapsed time free
POST /travel/average-speed$0.002Developer Utilities
Travel points value calculator
cents per point vs baseline, free
POST /travel/award-value$0.002Developer Utilities
Cycling time estimator
bike ride duration from distance and speed, free
POST /travel/cycling-time$0.002Developer Utilities
Travel distance unit converter
kilometers, miles and nautical miles, free
POST /travel/distance-unit-convert$0.002Developer Utilities
ETA calculator
estimated arrival clock time from departure, free
POST /travel/eta-calculator$0.002Developer Utilities
MPG to L/100km converter
US MPG, imperial MPG and liters per 100 km, free
POST /travel/fuel-economy-convert$0.002Developer Utilities
Luggage linear inches calculator
L+W+H and airline limit check, free
POST /travel/luggage-linear-inches$0.002Developer Utilities
Luggage volume calculator
bag liters and cubic inches from L×W×H, free
POST /travel/luggage-volume$0.002Developer Utilities
Airline miles value calculator
cents per point from cash fare and taxes, free
POST /travel/miles-to-points$0.002Developer Utilities
Driving range remaining calculator
fuel or charge × economy, free
POST /travel/range-remaining$0.002Developer Utilities
Road trip time calculator
driving time and arrival offset, free
POST /travel/road-trip-time$0.002Developer Utilities
Speed unit converter
km/h, mph, knots, m/s, free
POST /travel/speed-unit-convert$0.002Developer Utilities
Timezone offset difference
hours between two UTC offsets, free
POST /travel/timezone-offset-diff$0.002Developer Utilities
Tire pressure by load calculator
adjust PSI for actual load, free
POST /travel/tire-pressure-load$0.002Developer Utilities
Road trip cost split
fuel and tolls per passenger free
POST /travel/trip-cost-split$0.002Developer Utilities
Trip fuel cost estimator
distance, MPG and fuel price, free
POST /travel/trip-fuel-cost$0.002Developer Utilities
Walking time estimator
distance and pace to duration, free
POST /travel/walking-time$0.002Developer Utilities
Amplitude, period & phase shift calculator
from A sin(Bx+C)+D
POST /trig/amplitude-period$0.002Developer Utilities
Angle of elevation calculator
distance and height to angle, free
POST /trig/angle-of-elevation$0.002Developer Utilities
Coterminal angle calculator
positive and negative within one turn
POST /trig/coterminal-angle$0.002Developer Utilities
Degrees minutes seconds converter
DMS ↔ decimal degrees either way
POST /trig/dms-to-decimal$0.002Developer Utilities
Double-angle calculator
sin(2x), cos(2x), tan(2x) from one angle
POST /trig/double-angle$0.002Developer Utilities
Arccosine calculator
acos(x) in degrees and radians, free
POST /trig/inverse-cos$0.002Developer Utilities
Arctangent calculator
atan and atan2 in degrees and radians
POST /trig/inverse-tan$0.002Developer Utilities
Law of cosines angle finder
three sides to all angles, free
POST /trig/law-of-cosines-angle$0.002Developer Utilities
Law of sines calculator
missing side or angle from a pair
POST /trig/law-of-sines$0.002Developer Utilities
Polar to rectangular converter
r and θ to cartesian x, y
POST /trig/polar-to-rectangular$0.002Developer Utilities
Reference angle calculator
degrees or radians, quadrant, free
POST /trig/reference-angle$0.002Developer Utilities
Right triangle trig solver
one side and acute angle, free
POST /trig/right-triangle-trig$0.002Developer Utilities
Sine cosine tangent calculator
sin, cos, tan, csc, sec, cot from an angle
POST /trig/sin-cos-tan$0.002Developer Utilities
Sine wave calculator
amplitude, period, phase, vertical shift, value at x
POST /trig/sine-wave$0.002Developer Utilities
Sum and difference angle calculator
sin cos tan of a±b, free
POST /trig/sum-difference$0.002Developer Utilities
Exact trig values calculator
sin cos tan radicals for special angles, free
POST /trig/trig-exact-values$0.002Developer Utilities
Miles to km converter
convert miles to kilometers, free
POST /conv/miles-to-km$0.002Developer Utilities
Bearing and heading calculator
compass direction between two points
POST /trig/bearing$0.002Developer Utilities
Feet to cm converter
convert feet to centimeters, free
POST /conv/feet-to-cm$0.002Developer Utilities
Triangular number calculator
n-th triangle and membership test
POST /math/triangular-number$0.002Developer Utilities
Harshad number checker
Niven test and quotient, free
POST /numth/harshad-number$0.002Developer Utilities
Rate constant from rate law calculator
k from measured rate, free
POST /chem/rate-constant-from-rate$0.002Developer Utilities
PEM Base64 encoder
64-char lines with BEGIN/END headers, free
POST /enc/base64-pem$0.002Developer Utilities
Absence percentage calculator
days absent over scheduled workdays
POST /fin/absence-percentage$0.002Developer Utilities
AAA triangle calculator
three angles and one side via law of sines
POST /math/aaa-triangle$0.002Developer Utilities
Absolute humidity calculator
grams of water vapor per cubic meter, free
POST /phys/absolute-humidity$0.002Developer Utilities
pH acidity classifier
acidic, neutral or basic from pH
POST /chem/acidity-classification$0.002Developer Utilities
Battery charge capacity calculator
Q from moles and electrons, free
POST /chem/battery-capacity-moles$0.002Developer Utilities
Buffer pH after acid addition
new pH from moles of strong acid, free
POST /chem/buffer-after-addition$0.002Developer Utilities
Buffer pH calculator
pH from pKa and concentrations, free
POST /chem/buffer-ph$0.002Developer Utilities
Half-cell reduction potential calculator
E from [Mⁿ⁺], E°, n
POST /chem/electrode-potential-reduction$0.002Developer Utilities
Equilibrium moles from total pressure calculator
gas stoichiometry, free
POST /chem/equilibrium-moles-from-pressure$0.002Developer Utilities
Electrochemical equivalents calculator
equivalents from charge Q/F
POST /chem/equivalents-from-charge$0.002Developer Utilities
Electrolysis charge calculator
Q=I·t from current and time, free
POST /chem/faraday-charge$0.002