Engineering Calculators
Calculators that combine units, with exact factors and the working shown. Every result can be copied or shared as a link.
- Face Velocity Calculator Airflow + filter, duct or hood size → face velocity (fpm, m/s), or solve for flow or area.
- Air Permeability Calculator Tester flow + test area (ISO 9237, ASTM D737 presets) → permeability in mm/s, L/m²/s, cfm/ft².
- SCFM to ACFM Calculator Standard ↔ actual gas flow (SCFM/ACFM, Nm³/h) at any temperature, pressure or altitude.
- Reynolds Number Calculator Velocity, diameter, density and viscosity in any units → Re and flow regime.
- Pipe Pressure Drop Calculator Flow + pipe size + material + fluid → pressure drop, velocity, Re and friction factor.
- Ideal Gas Law Calculator Solve PV = nRT for P, V, n or T in any pressure, volume and temperature units.
- Bubble Point Pore Size Calculator Bubble-point pressure + wetting liquid → largest pore size (Young–Laplace), or the reverse.
- Ohm's Law Calculator Any two of volts, amps, ohms and watts → the other two.
- Bulk Unit Converter Paste a column or table from Excel, convert every value, copy back or download CSV.