Engineering & construction
517 engineering and construction calculators: electrical circuits, mechanics, materials, structures and building quantities. Results with the formula and units in view, so you can check a design before you build it, free in your browser.
Average velocity from displacement calculator
A net shift of 100 units in 20 time units is an average velocity of 5, positive along your axis: the calculator divides signed displacement by elapsed time, in…
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Two-phase accelerate-cruise calculator
Accelerating at 2 m/s² up to 10 m/s and then cruising for 5 s covers 75 m in 10 s. Enter acceleration, cruise speed and cruise time to get each phase and the…
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Velocity-time graph area calculator
Going from 10 to 20 m/s in 5 s covers a displacement of 75 m, the area under that line on a velocity-time graph.
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Friction stopping distance calculator
An object sliding at 10 m/s with a friction coefficient of 0.3 stops after 16.9952702163 m: enter the speed and the coefficient to get the sliding distance and…
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Projectile clears wall calculator
Launch at 20 m/s and 45 degrees toward a 5 m wall 30 m away and the path passes at 7.9350375 m, clearing the top by 2.9350375 m. Free in your browser.
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Optimal launch angle calculator
On flat ground with no air, the farthest throw always leaves at 45 degrees: at 20 m/s that reaches 40.78864851911713 m, the speed squared divided by g.
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Projectile velocity at time
One second after a launch at 20 m/s and 45°, how fast is the ball moving and where is it pointing? Get the speed, the angle above the horizontal and the…
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Atwood machine tension calculator
Two masses of 5 kg and 3 kg over an ideal pulley, with g at 9.81 m/s², pull the cord taut at 36.7875 N: the calculator applies twice m1 times m2 times g over…
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Frictionless incline acceleration calculator
On a 30-degree frictionless ramp a block accelerates at 4.903325 m/s², exactly half of standard gravity.
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Elevator apparent weight calculator
A 70 kg rider in a cabin accelerating upward at 2 m/s² reads 826 N on the scale, with gravity at 9.8 m/s².
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Blocks in contact force calculator
Pushing a 4 kg block with 20 N against a 6 kg block gives both an acceleration of 2 m/s² and a contact force of 12 N between them.
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Equilibrant force calculator
Forces of (3, 4) and (−1, 2) add up to a resultant of (2, 6), so the force that balances them is (−2, −6), with the same size and the opposite direction.
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Action-reaction force calculator
Enter the push one body gives another and get the push it receives back: 50 N to the right returns 50 N to the left, written as minus 50.
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Wedge mechanical advantage calculator
A wedge with a 12 cm slope and a 3 cm thick end has an ideal mechanical advantage of 4: the output force is four times your effort, before friction.
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Force for constant speed calculator
Pulling a 200 N crate at constant speed on a floor with a friction coefficient of 0.25 takes 50 N: on level ground the force is the coefficient times the…
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Period of circular motion calculator
Divide the circumference by the speed and you have the period: an object on a 2 m circle moving at π m/s completes one lap every 4 seconds, 0.25 laps per…
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Time to slide down incline calculator
On a 30° ramp with a friction coefficient of 0.2, a block starting from rest covers 10 m in 2.49814137366 s.
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RPM to angular frequency calculator
60 rpm is exactly 2π rad/s, or 1 Hz: the calculator turns revolutions per minute into angular frequency with ω = 2π × rpm / 60, and adds the frequency in hertz…
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Conical pendulum calculator
A 1 m string held at 30° from the vertical traces a circle of 0.5 m radius. Enter length, angle and gravity to get the period and speed of each orbit, plus cone…
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Tangential acceleration calculator
An angular acceleration of 2 rad/s² at a radius of 3 m gives a tangential acceleration of 6 m/s². Enter both values to get the signed result and its magnitude…
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Conservation of energy calculator
An object released from rest at 10 m reaches 14 m/s by the time it drops to 0 m, with gravity at 9.8 m/s².
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Change in potential energy calculator
Lifting 2 kg by 5 m with gravity at 9.8 m/s² stores 98 J of potential energy: enter the mass, gravity and height change to get the gain, or a negative value…
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Impact force calculator
Stopping 450 J of kinetic energy within 0.05 m takes an average force of 9,000 N. Enter the energy to absorb and the crush, padding or braking distance to see…
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Power to lift load calculator
Raising 50 kg by 10 m in 5 seconds takes 4903.325 J of work and 980.665 W of average power under standard gravity. Use it to size a hoist, winch or lift motor.
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Work to raise a mass calculator
Lifting 2 kg through 5 m with g at 9.8 m/s² takes 98 J of work against gravity. Enter mass, local g and the lift height and get the energy a slow, steady lift…
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Climbing power calculator
A 70 kg hiker who gains 100 m in 600 s does 68,646.55 J of work against gravity. Enter body mass, vertical gain and time, and the tool turns that work into…
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Input power required calculator
A motor that must deliver 750 W at 85% efficiency needs an input of 882.352941176 W. Enter the useful output power and the efficiency as a fraction to get the…
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Kinetic energy lost in collision calculator
When a 2 kg body at 4 m/s sticks to a 3 kg body at −2 m/s, 21.6 J of the 22 J of kinetic energy turns into heat, deformation or sound.
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Center of mass velocity calculator
Two particles, 2 kg at 3 m/s and 1 kg at rest, have a center of mass moving at 2 m/s and a total momentum of 6 kg·m/s.
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Coefficient of restitution calculator
A ball that approaches at 10 m/s and separates at 6 m/s has a coefficient of restitution of 0.6. Enter both relative speeds in the same unit to see how bouncy…
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Rocket thrust calculator
An engine expelling 250 kg of propellant per second at 3000 m/s produces 750,000 N of thrust. Enter the mass flow rate and the effective exhaust velocity to get…
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Final angular velocity calculator
A wheel spinning at 10 rad/s that gains 2 rad/s every second reaches 20 rad/s after 5 seconds: the calculator adds αt to ω₀ and lays out each step.
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Impulse from force graph calculator
A pulse that peaks at 100 N and lasts 0.04 s delivers 2 N·s, the area of the triangle under its force-time graph.
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Two-dimensional collision calculator
A 2 kg body moving at 3 m/s along x that sticks to a 4 kg body moving at −1 and 2 m/s leaves with it at 1.3743685419 m/s, at 75.9637565321°.
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Calculate Concrete Volume Needed With Waste Allowance
A 12 by 10 foot slab 0.5 feet thick is 2.222222 cubic yards, and 2.444444 once a 10 % waste allowance is added.
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Estimate decking boards needed from area, width, and gap
Twenty square metres of deck with 0.14 m boards and a 0.005 m gap need 138 boards. Enter your area, board width and spacing to get a whole-board count that…
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Calculate fence post count and even spacing
A 30 foot run with posts no more than 8 feet apart needs 4 equal sections, 5 posts and an actual spacing of 7.5 feet.
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Calculate gravel volume for a driveway and estimate its weight
120 square metres of driveway at a depth of 5 cm need 6 cubic metres of gravel, about 9.6 tonnes. Enter your area and finished depth to check a quote or a…
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Calculate combined insulation R-value from multiple layers
Layers of R-0.45, R-13 and R-5 add up to R-18.45. List each layer's R-value in the same units to compare insulation stacks or check a renovation spec before you…
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Estimate HVAC BTU needed for room size
A 300 square foot room with an 8 foot ceiling, average sun and 2 people needs about 6000 BTU per hour, half a ton of cooling.
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Calculate wallpaper rolls needed with pattern-repeat waste
A 12 by 8 ft wall is 96 sq ft; with 10% pattern waste it needs 105.6 sq ft of coverage, so rolls covering 28 sq ft each mean buying 4.
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Angular momentum calculator
A flywheel with a moment of inertia of 2.5 kg·m² spinning at 4 rad/s carries an angular momentum of 10 kg·m²/s: the calculator multiplies I by ω and keeps the…
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Hollow Cylinder Moment of Inertia Calculator
A 12 kg tube with radii of 0.2 m inside and 0.5 m outside has a moment of inertia of 1.74 kg·m² about its long axis.
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Rod moment of inertia about one end
A 2 kg rod 1.5 m long, pivoted at one end, has a moment of inertia of 1.5 kg·m²: enter mass and length and the one-third factor is applied for you, with no…
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Rotational Power Calculator
A shaft carrying 120 N·m at 25 rad/s transmits 3000 W. Multiply torque by angular velocity measured at the same operating point to check motors, gearboxes and…
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Angular to arc distance calculator
A wheel with a 0.35 m radius that turns one full revolution, 2π radians, rolls 2π × 0.35 m, its whole circumference: the calculator multiplies the radius by the…
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Gravitational field strength calculator
Earth's mass of 5.972 × 10²⁴ kg at 6,371,000 m from its centre gives a field of 9.81997342622 m/s²: enter any mass and distance to get the pull a test object…
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Hollow sphere moment of inertia
A thin spherical shell of 3 kg and radius 2 m has a moment of inertia of 8 kg·m² about any diameter, from I = (2/3) mr².
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Rolling shapes race calculator
On a 30° ramp, a solid sphere beats a solid cylinder, which beats a thin hoop: the smaller the inertia factor, the faster a shape rolls.
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Torque Wrench Force Calculator
Reaching 120 N·m with a wrench 0.5 m long takes 240 N at the handle. Enter the target torque and the effective length to get the pull, and see why a longer…
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Escape energy calculator
Enter Earth's 5.972 × 10²⁴ kg and a launch radius of 6,371,000 m, add your object's mass, and you get the ideal minimum energy to leave the planet for good.
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Gravitational potential calculator
At 6,371,000 m from the centre of a 5.972 × 10²⁴ kg mass, the size of the Earth, the gravitational potential is −62,563,050.6985 J/kg.
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Orbit altitude from period calculator
Pick the orbital period you need and get the height above the surface that delivers it: for a 90-minute Earth orbit, enter 5400 seconds with the planet's size…
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Synchronous orbit radius calculator
For Earth, with a mass of 5.9722e24 kg and a sidereal day of 86164.0905 s, a synchronous orbit sits 42164.2437691 km from the centre.
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Vis-viva calculator
With μ of 398600.4418 km³/s², a distance of 7000 km and a semi-major axis of 10000 km, the orbital speed is 8.60382451787 km/s.
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Mutual gravitational acceleration calculator
Two bodies feel the same gravitational pull, but the lighter one accelerates more: enter the Earth, the Moon and 384,400,000 m between their centres to see each…
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SHM maximum acceleration calculator
An oscillation with a 0.15 m amplitude at 4 rad/s reaches a peak acceleration of 2.4 m/s². Enter amplitude and angular frequency to get the largest acceleration…
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Mass-spring period calculator
Hang 2 kg on a spring of 50 N/m and find how long one complete bounce takes, in seconds. Enter the mass and the spring constant to get the period of an ideal…
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SHM velocity calculator
With an amplitude of 5 m and an angular frequency of 2 rad/s, an oscillator 3 m from equilibrium moves at 8 m/s.
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Second-class lever calculator
A wheelbarrow carrying 200 N at 0.4 m from the wheel, lifted at handles 1.2 m from it, needs 66.6666666667 N of effort, a mechanical advantage of 3.
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