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Tool Corner
16 free tools

Engineering Calculators

Sixteen calculators covering the core equations of mechanics, materials, fluids and electrical theory — all in SI units, each with its formula shown.

Curated and maintained by Jogeswar, MSc, PMP — Tool CornerEvery calculator listed here is built and checked in-house
Browse by type
Mechanics & Energy
5 calculators
Electronics
4 calculators
Materials & Structures
4 calculators
Force Calculator
F = m·a
Torque Calculator
N·m
Work Calculator
W = F·d·cosθ
Power Calculator
Watts & hp
Kinetic Energy
E = ½mv²
Stress Calculator
Force over area
Strain Calculator
ε = ΔL / L₀
E
Young's Modulus
Material stiffness
Beam Load
Reactions & bending moment
Pressure Calculator
Pa, bar, psi
Fluid Pressure
P = ρgh at depth
Reynolds Number
Laminar or turbulent
Ω
Ohm's Law
Volts, amps, ohms, watts
Ω
Resistance Calculator
R = ρL / A
New
Resistor Colour Code
Decode 4, 5 and 6-band resistors
New
LED Resistor
Size the series resistor for an LED

Four domains, one unit system

The tools group into mechanics (force, torque, work, power, kinetic energy), materials (stress, strain, Young's modulus, beam loads), fluids (pressure, fluid pressure, Reynolds number) and electrical (Ohm's law, resistance). Everything works in SI base units throughout, because mixing systems is the single most common source of an answer that is wrong by orders of magnitude while looking entirely reasonable.

Mechanics builds in a chain

Force from the Force Calculator becomes a moment when applied at a distance, which is the Torque Calculator. Move that force through a displacement and you have work, from the Work Calculator; divide by time and you have power, from the Power Calculator. Give the mass motion instead and the same energy shows up as kinetic energy, from the Kinetic Energy. Understanding them as one chain rather than five formulas makes the units fall into place.

Material behaviour, and where it stops being linear

The Stress Calculator, Strain Calculator and Young's Modulus describe the elastic region — the part of the stress-strain curve where a material returns to its original shape. Past the yield point none of this applies, and permanent deformation begins. The Beam Load handles the statics of a simply supported beam: support reactions and maximum bending moment, the inputs to any bending stress check.

Fluids and flow regime

The Pressure Calculator handles force over area; the Fluid Pressure adds depth and density for hydrostatic pressure. The Reynolds Number answers a different kind of question — not how much, but what kind: below roughly 2,300 flow in a pipe is laminar and predictable, above roughly 4,000 it is turbulent, and between them it is transitional and genuinely hard to model.

Study tools, not design tools

Every calculator here uses idealised cases with no safety factors, no buckling or fatigue check, and no allowance for real-world tolerances, temperature effects or dynamic loading. Structural and electrical design is governed by codes — the Eurocodes, BS 7671 and their equivalents — and must be carried out by a qualified engineer. Use these to learn, to check intuition and to sanity-test a figure, never to specify anything that will be built.

Related categories

Converters
Metric and imperial units
Math & Numbers
Percentages, fractions and algebra
Construction & DIY
Concrete, paint, tiles and flooring
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