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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.
MMolarity & Dilution Calculator (C1V1=C2V2)
Find molarity from mass and molar mass, solve any variable of the C1V1=C2V2 dilution equation, or plan a serial dilution.
KEKinetic Energy Calculator
Solve kinetic energy, mass, or velocity from KE = ½mv², with velocity in m/s, km/h, mph, or ft/s.
☢Half-Life / Radioactive Decay Calculator
Solve remaining amount, initial amount, half-life, or elapsed time from N = N₀·(½)^(t/T), with decay constant and mean lifetime.
🔥Specific Heat Calculator (Q=mcΔT)
Solve heat, mass, specific heat, or temperature change from Q = mcΔT, with presets for common substances.
🎯Projectile Motion Calculator
Compute range, maximum height, time of flight, and impact velocity from launch speed, angle, and height.
P⇌Gas Laws Calculator (Boyle / Charles / Gay-Lussac / Combined)
Two-state gas law solver for P₁V₁/T₁ = P₂V₂/T₂ — pick Boyle, Charles, Gay-Lussac, or combined and solve any variable.
%Percent Yield Calculator
Solve percent yield, actual yield, or theoretical yield from % yield = actual ÷ theoretical × 100.
τTorque Calculator
Solve torque, radius, force, or angle from τ = r·F·sinθ, with results in N·m and lb·ft.
🔦Snell's Law / Refraction Calculator
Solve n1·sinθ1 = n2·sinθ2 for any angle or refractive index, with critical-angle and total-internal-reflection detection.
🪐Gravitational Force, Escape & Orbital Velocity Calculator
Compute Newton's gravitational force F=Gm1m2/r², plus escape and orbital velocities, solving for any variable.
⚡Coulomb's Law Calculator
Solve F = k·q1q2/r² for force, charge or separation, with attraction/repulsion detection and µC/nC/C units.
🎱Momentum & Impulse Calculator
Solve linear momentum p=mv and impulse J=FΔt=mΔv for any variable, with change in velocity from impulse.
⚙Work, Energy & Power Calculator
Solve mechanical work W=F·d·cosθ and power P=W/t for any variable, in joules and watts.
🧪Beer–Lambert Law Calculator
Solve A = ε·l·c for absorbance, molar absorptivity, path length or concentration, with %-transmittance.
⚗Stoichiometry (Mole-Ratio) Calculator
Convert between two species in a balanced reaction using their coefficients and the mole ratio, in moles or grams.