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
Excess electrons calculator
electron count from charge, free
POST /phys/excess-electrons$0.002Developer Utilities
Exoplanet calculator
Kepler period or axis from stellar mass
POST /phys/exoplanet$0.002Developer Utilities
Fan airflow calculator
rate from diameter and RPM
POST /phys/fan$0.002Developer Utilities
Fermi level calculator
energy from electron density, free
POST /phys/fermi-level$0.002Developer Utilities
Flow rate calculator
Q from velocity and pipe area
POST /phys/flow-rate$0.002Developer Utilities
Foot-pounds of energy calculator
grains and fps to ft-lbf, free
POST /phys/foot-pounds-of-energy$0.002Developer Utilities
Free fall distance calculator
d = ½gt² from time, free
POST /phys/free-fall-distance$0.002Developer Utilities
Free fall height calculator
h = ½gt² from fall time, free
POST /phys/free-fall-height$0.002Developer Utilities
Frequency of light calculator
f = c / λ in hertz, free
POST /phys/frequency-of-light$0.002Developer Utilities
Friction coefficient calculator
μ = Ff / N, kinetic or static
POST /phys/friction-coefficient$0.002Developer Utilities
Friction factor calculator
Darcy f from Re and ε/D
POST /phys/friction-factor$0.002Developer Utilities
Froude number calculator
Fr=V/√(gL) from velocity and length
POST /phys/froude-number$0.002Developer Utilities
Gear ratio RPM calculator
output shaft speed from tooth counts
POST /phys/gear-ratio-rpm$0.002Developer Utilities
Gay-Lussac's law calculator
final pressure from kelvin temperature, free
POST /phys/gay-lussacs-law$0.002Developer Utilities
Generator power calculator
watts from voltage, current and PF
POST /phys/generator-power$0.002Developer Utilities
Ground speed calculator
TAS, wind speed and wind angle
POST /phys/ground-speed$0.002Developer Utilities
Hair diffraction calculator
diameter from λ, L and Δy
POST /phys/hair-diffraction$0.002Developer Utilities
Hall coefficient calculator
R_H = V_H t / (I B) in m³/C
POST /phys/hall-coefficient$0.002Developer Utilities
Heisenberg uncertainty calculator
Δp min from Δx and ħ
POST /phys/heisenberg-uncertainty$0.002Developer Utilities
Helical coil inductance calculator
L from turns, radius and length
POST /phys/helical-coil$0.002Developer Utilities
Helmholtz resonator calculator
resonance frequency from c, A, L, V
POST /phys/helmholtz-resonator$0.002Developer Utilities
Hoop stress calculator
thin-walled vessel σ = PD/(2t)
POST /phys/hoop-stress$0.002Developer Utilities
Hubble's law calculator
recessional velocity from distance, free
POST /phys/hubbles-law$0.002Developer Utilities
Hydraulic gradient calculator
i=(h1-h2)/L from heads and distance
POST /phys/hydraulic-gradient$0.002Developer Utilities
Hydraulic radius calculator
R = A/P from area and perimeter
POST /phys/hydraulic-radius$0.002Developer Utilities
Ideal gas temperature calculator
T = PV/nR in kelvin
POST /phys/ideal-gas-temperature$0.002Developer Utilities
Ideal gas pressure calculator
P=nRT/V in pascals, free
POST /phys/ideal-gas-pressure$0.002Developer Utilities
Ideal transformer calculator
secondary voltage, current or turns
POST /phys/ideal-transformer$0.002Developer Utilities
Immersed weight calculator
apparent weight in a fluid, free
POST /phys/immersed-weight$0.002Developer Utilities
Insertion loss calculator
IL = 10·log10(Pin/Pout) in dB
POST /phys/insertion-loss$0.002Developer Utilities
Internal resistance calculator
r = (ε − V) / I, free
POST /phys/internal-resistance$0.002Developer Utilities
Intrinsic carrier concentration calculator
n_i from N_c, N_v, E_g
POST /phys/intrinsic-carrier-concentration$0.002Developer Utilities
Knudsen number calculator
Kn=λ/L from mean free path
POST /phys/knudsen-number$0.002Developer Utilities
J-pole antenna calculator
half-wave, quarter-wave and stub lengths
POST /phys/j-pole-antenna$0.002Developer Utilities
Kepler third law
satellite period from axis and mass
POST /phys/kepler-third-law$0.002Developer Utilities
Laser spot size calculator
focused diameter from λ, f and D
POST /phys/laser-spot-size$0.002Developer Utilities
LED current calculator
series LED current in amperes, free
POST /phys/led$0.002Developer Utilities
Lensmaker's equation
thin-lens focal length from n, n_m, R1, R2
POST /phys/lensmakers-equation$0.002Developer Utilities
Linear actuator force calculator
F from torque, lead, efficiency
POST /phys/linear-actuator-force$0.002Developer Utilities
Lorentz force calculator
F = q(E + v × B) vector
POST /phys/lorentz-force$0.002Developer Utilities
Lumen calculator
flux from candela and steradians, free
POST /phys/lumen$0.002Developer Utilities
Magnetic declination calculator
from true and compass bearings
POST /phys/magnetic-declination$0.002Developer Utilities
Magnetic dipole moment calculator
m = I A in A·m²
POST /phys/magnetic-dipole-moment$0.002Developer Utilities
Magnetic force on a current-carrying wire
F = I L B sin(θ)
POST /phys/magnetic-force-on-current-carrying-wire$0.002Developer Utilities
Magnetic moment calculator
current loop μ = N·I·A, free
POST /phys/magnetic-moment$0.002Developer Utilities
Magnitude of acceleration
|a| from ax, ay, az, free
POST /phys/magnitude-of-acceleration$0.002Developer Utilities
Manometer calculator
P=ρ·g·h from column height in Pa, free
POST /phys/manometer$0.002Developer Utilities
Mass to density calculator
ρ=m/V in kg/m³, free
POST /phys/mass-to-density$0.002Developer Utilities
Maximum height projectile motion
peak height from v, angle, g
POST /phys/maximum-height-projectile-motion$0.002Developer Utilities
Mixed-air temperature calculator
two air streams, free
POST /phys/mixed-air$0.002Developer Utilities
AHU mixed air temperature
two streams by mass flow
POST /phys/mixed-air-temperature$0.002Developer Utilities
AM modulation index calculator
m = Am / Ac, dimensionless
POST /phys/modulation$0.002Developer Utilities
Mohr's circle calculator
principal stresses and max shear
POST /phys/mohr-circle$0.002Developer Utilities
MOSFET threshold voltage
Vth from VFB, gamma, phi_s, VSB
POST /phys/mosfet-threshold-voltage$0.002Developer Utilities
NE555 astable calculator
frequency and duty cycle from R1 R2 C
POST /phys/ne555-astable$0.002Developer Utilities
Newton's third law calculator
equal and opposite reaction force
POST /phys/newtons-third-law$0.002Developer Utilities
NPSH calculator
net positive suction head in metres from P, ρ, g
POST /phys/npsh-net-positive-suction-head$0.002Developer Utilities
Ohm's law current calculator
I=V/R in amperes, free
POST /phys/ohms-law-current$0.002Developer Utilities
Ohm's law power calculator
watts from any two of V, I, R
POST /phys/ohms-law-power$0.002Developer Utilities
Open channel flow calculator
Manning Q from A, R, S, n
POST /phys/open-channel-flow$0.002