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Science Tools
Free physics and chemistry calculators — Ohm's law, LED resistors, voltage dividers, density, force, the ideal gas law, pH, and molar mass — computed instantly and privately in your browser.
ΩV
Ohm's Law Calculator
Solve for voltage, current, resistance and power from any two known values.
LEDLED Resistor Calculator
Find the current-limiting resistor for an LED, plus the nearest E12 value and power.
V÷Voltage Divider Calculator
Compute the output voltage and current of a two-resistor voltage divider.
PElectrical Power Calculator
Compute power, voltage, current or resistance from any two known values.
λfWavelength & Frequency
Convert between wavelength and frequency for light, sound or a custom wave speed.
ρDensity Calculator
Enter any two of density, mass and volume to compute the third using density = mass / volume.
FForce Calculator (F=ma)
Newton's second law: enter any two of force, mass and acceleration to compute the third.
PVIdeal Gas Law (PV=nRT)
Solve PV = nRT for any variable by entering the other three, with R = 8.314.
pHpH Calculator
Enter pH, pOH, [H+] or [OH-] and get the others plus acidic, neutral or basic.
MMolar Mass Calculator
Type a chemical formula to get its molar mass in g/mol and a per-element breakdown.