Linear and volumetric thermal expansion of an isotropic material. Linear: ΔL = α·L₀·ΔT, L₁ = L₀·(1+α·ΔT). Volumetric: ΔV = 3α·V₀·ΔT (β = 3α for isotropic solids). Built-in typical α for carbon/alloy steel, aluminum, copper, austenitic stainless, titanium and glass, plus custom. ΔT in K or °C, length in mm, volume in mm³.

Math & Numbers

Thermal Stress Calculator (σ = E·α·ΔT)

Thermal stress in a fully constrained member under a uniform temperature change: σ_th = E·α·ΔT. Built-in typical Young's modulus E and expansion coefficient α for carbon/alloy steel, aluminum, copper, austenitic stainless and titanium, plus custom values. ΔT in K or °C (same magnitude), result in MPa. Heating (ΔT>0) → compressive stress in the member.

Math & Numbers

Thermal Comfort PMV-PPD (ISO 7730 / Fanger)

Compute the thermal comfort indices PMV (Predicted Mean Vote, −3 cold..+3 hot) and PPD (Predicted Percentage Dissatisfied, %) per ISO 7730 / ASHRAE 55, using the Fanger equations. Inputs: air temperature Ta, mean radiant temperature Tr, relative air velocity v_ar, relative humidity φ, metabolic rate M (met; 1 met = 58.2 W/m²), clothing insulation Icl (clo; 1 clo = 0.155 m²·K/W), and external work W (defaults to 0). The clothing surface temperature Tcl is solved iteratively. Returns a 7-level ASHRAE sensation label.

Math & Numbers

Three-Phase Power Calculator

Calculate active, reactive, and apparent power for a balanced three-phase system: S=√3·U·I, P=√3·U·I·cosφ, Q=√3·U·I·sinφ. Also returns the power-factor angle φ and verifies the power triangle.

Math & Numbers

Transformer Impedance Transfer Calculator

Reflect an impedance through an ideal transformer: Z' = a²·Z, where a = N₁/N₂. Supports secondary→primary and primary→secondary directions; a can be given directly or derived from N₁/N₂. Also returns admittance Y and reflected admittance.

Math & Numbers

Transformer Turns Ratio Calculator

Ideal transformer ratio: a = N₁/N₂ = V₁/V₂ = I₂/I₁. Given turns, voltage, or current on either side, compute a and the corresponding voltage/current on the other side; verifies V₁·I₁ = V₂·I₂.

Math & Numbers

Unit Converter with Formula Display

Convert common physical, chemistry, cooking, medical, and information units with the formula and dimensional analysis visible.

Finance

Unit Price Calculator

Compare supermarket product prices by normalizing them to a common unit (per 100g, per liter, per piece, etc.). Enter products as 'name, price, quantity, unit' per line. Ranks from cheapest to most expensive per unit and shows savings vs the most expensive option.

Math & Numbers

Torque Calculator (τ = rF sinθ)

Compute torque, force, or lever arm from τ = r·F·sin(θ), with the perpendicular force component shown

Math & Numbers

Thermodynamics (Gibbs Free Energy) Calculator

Calculate Gibbs free energy ΔG = ΔH − TΔS, reaction spontaneity, equilibrium temperature, and equilibrium constant K.

Calculator

Tile Coverage Estimator

Estimate how many tiles you need to cover a room, including layout-aware waste (straight, 45° diagonal, herringbone, basketweave), boxes to buy, grout volume and weight, and an optional cost total. Enter room and tile dimensions plus joint width to get a ready-to-order material list.

Calculator

Tire Size & Gear Ratio Calculator

Enter a tire size (285/70R17), differential/final-drive ratio, and transmission gear ratios to compute the true overall tire diameter, circumference, revolutions per mile/km, an RPM × gear speed table, effective final drive after a tire change, and speedometer error. Metric or imperial units, with optional before/after tire comparison.