📐 Mechanical Engineering 18
Bearing Stress CalculatorBearing stress for bolts, pins and rivets, with projected area, safety factor and pass/fail.Bolt Load CalculatorFind how much tension, shear or combined load a bolt — or a group of bolts — can actually carry, with allowable capacity, a clear pass / fail...Factor of Safety CalculatorThe safety margin between a material’s strength and the applied stress.Gear Ratio CalculatorGear ratio from tooth counts, with output speed, torque, and compound-train staging.Mechanical Force CalculatorForce from acceleration, weight, pressure, torque, friction, centripetal motion, springs or impact.Mechanical Stress CalculatorAxial, bending, shear, bearing and torsional stress, with a safety factor and yield check.Moment of Inertia CalculatorArea and mass moment of inertia for common shapes.Pressure Vessel (Hoop Stress) CalculatorHoop and longitudinal stress in a thin-wall cylinder or sphere, checked against allowable, with min thickness.Pulley & Belt Length CalculatorBelt length for a two-pulley drive, with speed ratio, output RPM, belt speed and wrap angles.Section Modulus CalculatorSection modulus, moment of inertia and bending capacity for beams, rounds, tubes and I-beams.Shaft Diameter CalculatorMinimum shaft diameter for combined torque and bending by the ASME method, from torque or power and speed.Shear Stress CalculatorShear stress in a pin, bolt, punched hole or beam, with a material-strength and safety-factor pass/fail check. Single or double shear, three section types.Spring Rate CalculatorFind helical spring rate from wire size, coil diameter and turns (k = Gd4/8D3N), or from measured load and travel. Spring index and Wahl shear-stress check.Strain CalculatorCalculate normal, thermal, lateral (Poisson) and shear strain, with microstrain and true-strain output. Metric and imperial.Torque CalculatorTorque from a force and lever arm, a motor’s power and speed, or a bolt spec.Weld Size CalculatorFind the right weld size for the job. Enter the plate thickness and the load, and get the required fillet leg, the effective throat, the code minimum and...Weld Strength CalculatorEnter a weld you already have — size, length and electrode — and find out how much load it can actually carry, with a clear pass / fail...Young’s Modulus CalculatorFind Young's modulus from a tension test and identify the material, or predict how far a part stretches under load. Hooke's law, metric and imperial.
📐 Fluid Mechanics 11
Bernoulli Equation CalculatorFind the pressure at a second point of a pipe, or the flow rate from a pressure drop (venturi), using Bernoulli with continuity and head loss.Drag Force CalculatorAerodynamic and hydrodynamic drag force F = half rho v-squared Cd A, with dynamic pressure and power to overcome.Friction Factor CalculatorDarcy and Fanning friction factor from Reynolds number and roughness, solved with Colebrook.Hydraulic Diameter CalculatorHydraulic diameter D_h = 4A/P for ducts, annuli and channels, to apply round-pipe flow formulas.Open-Channel Flow CalculatorOpen-channel flow by the Manning equation for trapezoidal, rectangular and triangular sections, with velocity.Orifice Flow CalculatorLiquid flow through an orifice or nozzle from pressure or head (Q = Cd A sqrt(2 dP/rho)), with discharge coefficients.Pipe Flow CalculatorFlow, velocity, pressure drop and pump power for a pipe, in one tool.Pressure Drop CalculatorPressure drop and pump head for fluid in a pipe - Darcy-Weisbach with automatic friction factor.Pump Horsepower CalculatorPump brake horsepower and motor size from flow and head, with efficiency and annual energy cost.Reynolds Number CalculatorThe Reynolds number and whether flow is laminar, transitional or turbulent.Tank Drain Time CalculatorTime for a tank to drain by gravity or pump - vertical or horizontal cylinder, rectangular and cone-bottom - with head, flow rates and a drain curve.
📐 Fasteners & Rivets 9
Rivet Edge Distance CalculatorHow far a rivet must sit from the edge to avoid tear-out - recommended minimum edge distance, a pass/fail check, and tear-out (shear-out) capacity.Rivet Grip Range CalculatorWhich blind (pop) rivet grip range fits your material - enter the stack thickness and rivet diameter to get the grip number, range and drill size.Rivet Length CalculatorWhat length rivet to buy for your grip - length = grip + tail allowance (about 1.5d for solid rivets), with standard-size rounding and a grip-to-diameter check.Rivet Pattern CalculatorLay out a rivet group over a plate - rows, columns and total count for a grid or staggered pattern, with pitch, gauge and edge checks.Rivet Pull-Out CalculatorWill a rivet hold in tension or pull through? Rivet tensile vs sheet pull-through capacity, the governing mode, and a pass/fail check.Rivet Shear Strength CalculatorWill the rivets hold? Shear capacity of a riveted joint per rivet and total, with a pass/fail verdict and the actual factor of safety against your load.Rivet Size CalculatorWhat diameter rivet for the joint - size it from sheet thickness, Unwin formula, or shear load, then round to the nearest standard size.Rivet Spacing CalculatorHow far apart to set rivets and how many a seam needs - pitch and rivet count with the usual 3d to 6d spacing and edge-distance checks.Rivet Type Selector: Blind vs Solid vs TubularWhich rivet type for your job? A four-question selector for blind vs solid vs tubular rivets, plus a side-by-side comparison.
⚡ Electrical Engineering 7
AC Impedance Calculator (Series RLC)Series RLC impedance, reactance, phase angle, power factor and resonant frequency at a given AC frequency.Capacitor & RC Time Constant CalculatorCapacitor energy, charge, RC time constant and charge/discharge voltage over time, with the 63% and 5-tau rules.Fault Current (Short-Circuit) CalculatorAvailable short-circuit current at a transformer secondary, with the minimum breaker interrupting rating (AIC).Motor Full-Load Amps (FLA) CalculatorMotor full-load amps for 3-phase, 1-phase and DC, with the NEC 125% conductor sizing figure.Power Factor Correction CalculatorCapacitor kVAR to correct power factor, with the apparent-power and current reduction it delivers.Three-Phase Power CalculatorReal, apparent and reactive power for a three-phase load, plus sizing current.Wire Size CalculatorMinimum wire size from ampacity and voltage drop, with the deciding factor shown.
📐 Structural Engineering 7
Beam Deflection CalculatorHow far a beam bends under load, checked against a safe deflection limit.Beam Load CalculatorReactions, shear and maximum bending moment for a loaded beam.Column Buckling CalculatorEuler buckling load from section, length and end conditions, with slenderness and a verdict.Load Combination CalculatorRank every ASCE 7 LRFD and ASD load combination from your nominal loads and find the governing case.Seismic Base Shear CalculatorSeismic base shear by the ASCE 7 equivalent lateral force method, with the R-factor and period cap and floor.Snow Load CalculatorRoof snow load by the ASCE 7 method with exposure, thermal, importance factors and the slope reduction.Wind Load CalculatorWind force on a wall, sign or panel by the ASCE 7 velocity-pressure method, with exposure and height.
📐 Civil Engineering 7
Bearing Capacity Calculator (Terzaghi)Ultimate and allowable bearing capacity of a shallow footing by the general bearing-capacity equation, with shape and groundwater.Concrete Volume CalculatorConcrete volume, bags and cost for slabs, footings, columns, walls and stairs, plus rebar.Excavation CalculatorExcavation volume for pits, trenches and piers, with soil swell, truckloads and haul cost.Rebar Development Length CalculatorRebar tension development length by the ACI 318 simplified method, with casting, coating and lightweight factors.Retaining Wall CalculatorGravity retaining wall stability - overturning, sliding and bearing checks with safety factors.Slope Stability Calculator (Infinite Slope)Infinite-slope factor of safety against sliding, with dry and seepage cases - the geotechnical slope check.Stormwater Runoff CalculatorPeak stormwater runoff by the Rational Method (Q = C i A), in cfs or m3/s, with surface coefficients.
📐 Thermodynamics & Heat Transfer 7
Heat Transfer CalculatorConduction, convection, resistance, U-value and LED junction temperature.Latent Heat CalculatorEnergy to melt, freeze, boil or condense a mass (Q = m L), with phase-change temperature, time and cost.LMTD & Heat Exchanger CalculatorLog mean temperature difference and heat duty (Q = U A LMTD) for counterflow or parallel-flow exchangers, with cross check.Pipe Heat Loss CalculatorRadial heat loss from an insulated pipe, in W/m and BTU/hr-ft, with the savings versus a bare pipe.R-Value CalculatorTotal R-value and U-factor of a layered wall or roof assembly, with a climate-zone code check.Sensible Heat CalculatorHeat energy to change a material temperature, in kWh and BTU, with heating time and cost.Thermal Expansion CalculatorLength change, shaft and hole diameter growth, and the expansion gap to leave.
📐 HVAC 6
CFM and Air Changes (ACH) CalculatorFind the airflow (CFM or m3/h) a room needs for a target air-change rate, or the ACH a fan delivers. Room-type presets, metric and imperial.Duct Static Pressure CalculatorFind the static pressure of a duct run - velocity, friction rate and total static pressure - for round or rectangular ducts. Darcy/Swamee-Jain, metric and imperial.Duct Velocity CalculatorFind air velocity in a round or rectangular duct from airflow and size, or size a duct for a target velocity. Recommended-range check, metric and imperial.Fan Laws (Affinity) CalculatorApply the fan affinity laws: change fan speed or impeller diameter and get the new airflow, pressure and power. Shows the cube-of-speed energy saving.Psychrometric CalculatorEnter dry-bulb temperature plus relative humidity, dew point or wet-bulb to get full moist-air properties: dew point, RH, wet-bulb, humidity ratio, enthalpy and specific volume.Ventilation Rate Calculator (ASHRAE 62.1)Required outdoor air by ASHRAE 62.1: combine the per-person and per-area rates for your occupancy type to size fresh-air ventilation. With Ez and CFM/L-s output.
📏 Conversions 4
Engineering Unit ConverterConvert pressure, force, torque, energy, power, flow and temperature, with a full unit table.Flow Rate ConverterConvert flow rate between GPM, L/s, L/min, m3/h, m3/s, CFM and ft3/s instantly, with common equivalents.Power ConverterConvert power between watts, kW, horsepower, BTU/hr, ft-lb/s and tons of refrigeration, with common equivalents.Torque ConverterConvert torque between N-m, lb-ft, lb-in, oz-in, kgf-m and kN-m instantly, with common equivalents.
📐 Materials 3
Corrosion Rate CalculatorCorrosion rate by weight loss, thickness loss or electrochemical method in mpy, mm/yr and um/yr, with corrosion-allowance remaining life and a pass/fail service-life check.Hardness Conversion CalculatorConvert hardness between Vickers, Brinell, Rockwell C and Rockwell B, with a steel tensile-strength estimate. ASTM E140-style correlations.Thermal Stress CalculatorThermal stress for restrained parts: fixed, partial, free, pipe, beam, rail, bolted and differential modes. Expansion, stress, force, yield pass/fail and charts.