Calculation tools for mechanical engineering
Design, calculate, verify, document. Over 80 engineer-reviewed calculators for design, drive technology, strength, manufacturing, automation and much more - standards-based and with live results.
Drive sizing
7Drive Sizing Calculator
ProSize the complete drivetrain: motor, gearbox, inertias and torques in a single calculator.
Torque, Speed & Power
FreeConvert between torque, speed and power: P = M·ω for rotating drives.
Gear Ratio & Transmission
FreeGear ratio i from tooth counts, diameters or a speed pair, reflecting speed, torque and inertia through the stage.
Motion Profile (s-v-a)
FreeKinematics of uniformly accelerated motion: solve the missing quantity from distance, velocity, acceleration and time.
Moment of Inertia
FreeMass moment of inertia of homogeneous bodies: solid cylinder, tube, cuboid, sphere, cone and ring.
Slider-Crank Mechanism
FreeSlider-crank mechanism: piston displacement, velocity and acceleration from crank and rod geometry.
Brake Sizing
FreeRequired braking torque, static and dynamic, plus braking energy and deceleration time.
Automation & handling
9Axis Move & Cycle Time
FreeCycle time of a positioning axis from multiple move and dwell segments: trapezoidal, triangular and S-curve profiles, segment time and peak velocity plus combined position, velocity and acceleration plots.
Ball Screw
FreeSize a ball screw: drive torque, speed from feed rate, critical speed with bearing factor, DN value, Euler buckling load and L10 life with traffic-light rating.
Rotary Indexing Table
FreeRotary indexing table: switching torque, cycle time and acceleration profile from station count, index time and table inertia.
Robot Flange Inertia
FreeInertia, static load moment and payload at the robot flange: parallel-axis contribution per mass, compared against datasheet limits with traffic-light rating.
Pneumatic Cylinder Air & Time
FreeAir consumption (standard volume) per stroke, cycle and minute plus approximate extension time of a pneumatic cylinder: piston and annulus area, compression ratio, load ratio and force balance.
Vacuum Gripper
FreeHolding force of a vacuum gripper and required number of suction cups: theoretical force per cup, load cases, safety factor with traffic-light rating.
Required Gripper Force
FreeRequired gripping force of a mechanical jaw gripper (friction or form fit): grip force per jaw from workpiece mass, acceleration, friction, jaw count and safety with traffic-light rating.
Shock Absorber
FreeSize industrial shock absorbers and end-position damping: energy per stroke and per hour and effective mass from moving mass, impact velocity, drive force and stroke with traffic-light rating.
Toggle Clamp Force
FreeToggle clamp force: mechanical advantage and resulting clamping force of a toggle clamp from actuation force, lever geometry and toggle angle.
Drive technology
7Cam design per VDI 2143
ProDesign motion laws, check characteristic values and calculate cam profiles per VDI 2143.
Gear calculation ISO 6336
FreeCalculate the load capacity of spur gears per ISO 6336.
Shaft critical speed
FreeEstimate the bending critical speed of shafts using the Rayleigh and Dunkerley methods.
Chain drive calculation
FreeDesign roller chain drives per ISO 606: chain length, ratio and power rating.
Cylinder force calculator
FreeCalculate extend and retract forces of pneumatic cylinders per ISO 15552.
Bevel Gear
FreeCalculate a straight bevel gear online: pitch cone angles, outer and mean pitch diameters, cone distance, virtual tooth number and tangential force with a sketch and traffic-light rating.
Worm Gear
FreeCalculate a cylindrical worm gear per DIN 3975 online: ratio, lead angle, diameters, centre distance, driving efficiency and self-locking with a traffic-light rating.
Strength
9Shaft strength DIN 743
FreeCalculate the safety verification for shafts and axles per DIN 743.
Beam deflection calculator
FreeCalculate deflection and bending stress of beams for common support and load cases.
Fatigue per Palmgren-Miner
FreeCalculate damage sum and fatigue life of load spectra per the Palmgren-Miner rule.
Buckling calculator
FreeVerify the buckling safety of compression members per Euler and Tetmajer.
Hertzian contact stress
FreeCalculate contact pressure and deformation for point and line contact using Hertz theory.
Area Moment of Inertia & Section Modulus
FreeCalculate area moment of inertia and section modulus of common cross-sections: rectangle, circle, tube, I- and U-profile.
Equivalent Stress (von Mises)
FreeCalculate equivalent stress online by the von Mises (distortion energy), Tresca (maximum shear) and Rankine (maximum principal stress) theories: plane stress state or combined shaft loading, principal stresses, Mohr's circle and a safety check with traffic-light rating.
Torsion & Twist
FreeCalculate torsional shear stress tau and angle of twist phi of shafts online: solid circle, circular tube, thin-walled closed Bredt sections and rectangle, with torsional section modulus and torsion constant plus shear check with traffic-light rating.
Pressure Vessel & Pipe
FreeCalculate wall thickness and stresses of pressure vessels and pipes online: boiler formula for thin-walled cylinders and spheres, Lamé for thick-walled pipes, equivalent stress per von Mises and Tresca, safety against yield with traffic light. Preliminary sizing.
Steel construction (EC3)
2Engineering mechanics
4Single-DOF Vibration
FreeCalculate the free and damped vibration of a single-degree-of-freedom system: natural frequency, damping ratio, decay and resonance.
Belt & Rope Friction
FreeCalculate belt and rope friction with the Euler-Eytelwein equation: force ratio, holding force and wrap angle.
Axial & Thermal Stress
FreeCalculate normal stress, strain and elongation of tension and compression rods, including thermal stress with restrained expansion.
Centrifugal Force
FreeCalculate the centrifugal force of rotating masses from speed or angular velocity and radius: centrifugal force and circumferential velocity.
Joining technology
7Bolted joint VDI 2230
FreeDesign and verify bolted joints per VDI 2230.
Interference fit DIN 7190
FreeDesign and verify cylindrical interference fits per DIN 7190.
Parallel key DIN 6892
FreeVerify parallel key joints per DIN 6892 against surface pressure.
Weld calculation EN 1993-1-8
FreeVerify fillet welds per EN 1993-1-8: weld stresses and design resistance.
Flange calculation EN 1092-1
FreeDesign flange joints per EN 1092-1 and AD 2000-B7: dimensions, bolts and gasket forces.
Pin & Bolt Joint
FreeVerify pin and bolt joints against shear, surface pressure and bending per Roloff/Matek.
Rivet Joint
FreeVerify riveted joints online: shear τ = F/(z·n·A) and bearing pressure σ_l = F/(z·d·t) with safety factors and traffic-light rating, single and double shear.
Machine elements
5Compression spring calculator
FreeCalculate cylindrical compression springs per DIN EN 13906-1: spring rate, forces and stresses.
Bearing life L10
FreeCalculate the basic rating life of rolling bearings per ISO 281.
Extension Spring
FreeCalculate spring rate, force and shear stress of cylindrical helical extension springs online: with initial tension F0, curvature correction after Bergsträßer or Wahl, stress check with traffic-light rating and PDF report.
Disc Spring (Belleville)
FreeCalculate Belleville disc springs to DIN 2093 (Almen-Laszlo) online: spring force F(s), nonlinear characteristic, factors K1/K2/K3 and edge stress with a traffic-light rating.
Torsion (Leg) Spring
FreeCalculate cylindrical torsion (leg) springs per DIN EN 13906-3 online: spring rate, moment per degree and bending stress with curvature correction and traffic-light rating.
Tolerances and fits
4Fit calculator ISO 286
FreeDetermine limit deviations, clearance and interference for hole and shaft per ISO 286.
Tolerance stackup Monte Carlo
FreeCalculate tolerance stackups per DIN 7186 arithmetically, statistically and via Monte Carlo simulation.
GD&T true position per ISO 1101
FreeEvaluate position tolerances per ISO 1101: actual deviation, true position and bonus tolerance.
General tolerances ISO 2768
FreeLook up limit deviations for linear and angular dimensions without individual tolerances per ISO 2768.
Sheet metal
2Bend allowance DIN 6935
FreeCalculate the flat length of sheet metal bends per DIN 6935.
Bending Force (Air Bending)
FreeCalculate the bending force for air bending in a V-die online: F = k·Rm·s²·b/V. With recommended die width, minimum bend radius and minimum flange length, live on every input.
Manufacturing
6Cutting data calculator
FreeDetermine cutting speed, spindle speed and feed for turning, milling and drilling.
Tapping Drill & Clearance Hole
FreeDetermine tapping drill diameters for metric threads per DIN 13 and clearance holes per EN 20273.
Wire & Tube Drawing Force
FreeCalculate the drawing force and stress in wire and tube drawing with Siebel's equation online: true strain, area reduction, ideal, friction and shear share with a drawing-limit check.
Cutting Force & Power (Kienzle)
FreeDetermine cutting force, power and machining time for turning, milling and drilling with the Kienzle model.
Punching & Shearing Force
FreeCalculate punching and shearing force and work for shear cutting of sheet metal.
Weld Heat Input
FreeDetermine heat input and specific energy of a weld from current, voltage and travel speed.
Surface engineering
1Materials & units
3Material properties
FreeLook up strength and material properties of common engineering materials.
Hardness Conversion HV/HB/HRC/Rm
FreeConvert hardness values between Vickers, Brinell, Rockwell C and tensile strength per ISO 18265.
Material Weight (Sheet, Tube, Profile)
FreeCalculate the weight of sheets, round bars, tubes and profiles from material density and volume.
Quality & metrology
1Fluid engineering
1Pumps & hydraulics
5NPSH Calculator (Cavitation)
FreeCalculate the available NPSH and cavitation margin of centrifugal pumps and check it against the required NPSH.
Pump Power & Head
FreeCalculate system head, hydraulic power and shaft and motor power of centrifugal pumps.
Specific Speed n_q
FreeDetermine the specific speed n_q and impeller type from flow rate, head and rotational speed.
Pump Affinity Laws
FreeConvert flow rate, head and power of centrifugal pumps for a changed speed or impeller diameter.
Positive Displacement Pump
FreeCalculate flow rate, torque and power of positive displacement pumps from displacement volume and pressure difference.
Thermodynamics & heat
7Ideal Gas Law
FreeSolve the ideal gas law online: from any three of pressure, volume, mass and temperature find the fourth. Mass form with R_s (gas selection) and molar form with R_m, including density.
Gas State Changes
FreeCalculate state changes of ideal gases online: isothermal, isobaric, isochoric, adiabatic and polytropic. From an initial state and one target value get the final state, boundary work, heat, internal energy and entropy with a p-V diagram and PDF.
Otto & Diesel Cycle
FreeCalculate the thermal efficiency of the ideal Otto and Diesel cycles online: enter compression ratio and isentropic exponent to get corner states, heat, mean effective pressure and the p-V diagram, live.
Heat Conduction
FreeCalculate heat flow, thermal resistance and temperature profile of multilayer walls and pipes online: Fourier's law, lambda selection for insulation and metals, temperature profile chart, PDF report.
Convection Coefficient
FreeCalculate the convective heat transfer coefficient α for forced pipe flow online: Reynolds, Prandtl and Nusselt number, Dittus-Boelter and Gnielinski, laminar Nu = 3.66, heat flow Q = α·A·ΔT and report PDF.
Heat Exchanger (LMTD/NTU)
FreeSize a recuperator online: LMTD method and eps-NTU method, counterflow and parallel flow, heat duty, outlet temperatures and temperature profile as a chart, live with every input.
Insulated Pipe Heat Loss
FreeCalculate the heat loss of insulated pipes online: pipe wall and insulation as a series of cylindrical thermal resistances, heat flow per length and total, surface temperature with touch-protection indicator and radial temperature profile.