All calculator tools

42 free tools across chemistry, physics, maths and accounts. Each has its own page and opens straight into the calculator.

Arrhenius Equation

k = A·e^(−Ea/RT). Leave one blank.

Basic Calculator

Simple +, −, ×, ÷ — for everyday calculations.

Beer–Lambert (A = εlc)

Leave one field blank.

Bohr Model

Buffer — Henderson–Hasselbalch

pH = pKa + log([A⁻]/[HA])

Clausius–Clapeyron

Leave either P₂ or ΔH vap blank.

Combined Gas Law (P₁V₁/T₁ = P₂V₂/T₂)

Leave exactly one blank (T in Kelvin).

Complex Numbers

Concentration

Molarity, moles, mass — fill any two.

Coulomb’s Law

Definite Integral ∫ₐᵇ f dx

Derivative f′(a), f″(a)

Dilution (M₁V₁ = M₂V₂)

Leave the unknown blank.

Electron Configuration

Equation Solver f(x)=0

Equivalent Weight

Eq. wt = Molar mass / n-factor

Force · Work · Energy

Computes F, KE, PE and W from whichever pairs you provide (g = 9.80665).

Gibbs Free Energy (ΔG = ΔH − TΔS)

Graham's Law of Effusion

r₁/r₂ = √(M₂/M₁) — molar mass ya formula.

Ideal Gas Law (PV = nRT)

Leave the unknown blank. R = 0.08206 L·atm/mol·K.

Income Tax Calculator (India)

New Regime — FY 2025-26 (AY 2026-27) slabs, §87A rebate & marginal relief ke saath.

K sp ↔ Solubility

Salt A x B y — enter either Ksp or s.

Kinematics (u, v, a, t, s)

Enter any 3 values, leave the rest blank — the rest are solved.

Limit lim x→a f(x)

Linear Regression

Mass ⇄ Mole

Formula + (mass ya moles) — doosra nikal jayega.

Matrix (3×3 / 2×2)

Rows me numbers space se, rows new line se.

Modern — de Broglie & Photon

de Broglie: enter m and v. Photon: enter λ only.

Nernst Equation

E = E° − (0.0592/n)·log Q (298 K)

Ohm’s Law & Power

Enter any 2 of V, I and R.

Optics — Lens / Mirror

Enter values with sign convention; leave one blank.

Oxidation Number

Formula + element → oxidation state. (Standard rules; peroxide/hydride exceptions differ.)

Permutation / Combination

Polynomial Roots

Coefficients, highest power first. x³−6x²+11x−6 → 1,-6,11,-6

Quantum Numbers

Radioactivity / Half-life

Leave one field blank. N = N₀(½)^(t/t½)

Scientific Constants

Tap a value to copy. CODATA / standard.

Statistics

Taylor Series (5 terms)

Van’t Hoff

Leave either K₂ or ΔH° blank.

Waves (v = fλ)

Enter any 2. Use the c button for light.

pH / pOH

Enter one value; the rest are derived (25 °C).