ENGINEERING CALCULATOR
Speed Calculator
Calculate linear speed from distance and time: v = d/t. Get results in m/s, km/h, mph, ft/s, and knots instantly. Works backwards to solve for distance or time. Built for engineers and machinists who need linear speed specs. Run your numbers, then get an instant quote when the motion spec is ready to machine.
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Free Online Tool
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Formula-Based Results
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Engineering Applications
Speed Calculator
Enter any two values, leave one blank to solve for it.
Speed (m/s)
10.0
Speed (km/h)
36.0
Speed (mph)
22.4
Speed (ft/s)
32.8
Speed (knots)
19.4
Formula
v = d / t | 1 m/s = 3.6 km/h = 2.23694 mph
Engineering Calculator
Speed Calculator
Enter distance and time to calculate speed, or solve for distance or time.
Enter distance
Enter time
m/s
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km/h
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mph
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ft/s
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knots
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Formula
Enter values and press Calculate.
HOW IT WORKS
How to Use the Speed Calculator
Three steps produce the answer, and every step is visible. Choose the variable (speed, distance, or time), enter the other two values, and read the solved result in all five speed units instantly.
Speed Formula
v = d / t
d = Distance (m)
t = Time (s)
Rearranged Forms
d = v × t | t = d / v
Distance from speed × time
Time from distance ÷ speed
Worked Examples
Three common cases: solve for speed, distance, or time. All results shown in multiple units.
300 m ÷ 25 s
= 12 m/s
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8 m/s × 600 s
= 4,800 m
|
120 mi ÷ 60 mph
= 2 h
Example 1 – Speed
12 m/s = 43.2 km/h = 26.8 mph
Example 2 – Distance
4.8 km (4,800 m)
Example 3 – Time
2 hours
Three Solve Modes
01
Solve for Speed
Enter distance and time to get speed in m/s, km/h, mph, ft/s, and knots.
v = d / t
02
Solve for Distance
Enter speed and time to find the distance covered.
d = v × t
03
Solve for Time
Enter speed and distance to determine the elapsed time.
t = d / vKey Concepts & Applications
Speed vs. Velocity
Speed is scalar (magnitude only); velocity is a vector (includes direction). On a straight line they match; in a loop, average speed can be positive while average velocity is zero.
Average vs. Instantaneous
This calculator returns average speed (total distance ÷ total time). Instantaneous speed is the speed at a single instant, as read on a speedometer.
Linear Motion in Machining
Used for CNC axis feeds, conveyor speeds, and actuator strokes. The result goes straight on the drawing for motion planning.
MACHINE DESIGN APPLICATIONS
Speed vs. Cutting Speed vs. Gear Speed vs. Motor Speed
Seven different tools are all called speed calculators — using the wrong one produces a wrong number. This page owns one and links the rest.
The speed calculator answers "how fast does this move along a line." The cutting speed calculator answers "how fast does the cutting edge meet the part." The feeds and speeds calculator sets spindle RPM and feed rate. The gear ratio calculator gives output shaft speed. Motor calculators convert power and speed into torque and horsepower. They share the word "speed," and almost nothing else.
Linear & Cutting Speed
Linear speed is distance divided by time: v = d/t. Cutting speed is the rate at which the cutting edge moves through the part surface: Vc = π × D × RPM / 1000.
- Speed Calculator: v = d / t — linear motion
- Cutting Speed Calculator: Vc = π × D × RPM / 1000 — surface speed
- One is distance over time; the other is spindle surface speed
Feeds, Speeds & Gears
Feeds and speeds determine spindle RPM and feed rate for milling. Gear ratio calculates output shaft speed through a gear pair. Each serves a different part of the motion chain.
- Feeds & Speeds: RPM = Vc × 1000 / (π × D) — spindle speed
- Gear Ratio: ratio = Z₂ / Z₁; RPM_out = RPM_in ÷ ratio
- Feed rate: FR = RPM × Z × fz — table movement
Motor Torque & Horsepower
Motor torque and horsepower calculators convert between power, speed, and torque. They are the tools for sizing motors and drives, not for motion planning.
- Motor Torque: T = P × 60 / (2π × RPM) — shaft torque
- Motor Horsepower: HP = T(ft·lbf) × RPM / 5252 — power output
- Use the right tool — landing on the wrong one gives meaningless numbers
Speed Questions
Speed FAQ
Divide the distance traveled by the time elapsed: v = d / t. For 300 m in 25 seconds, speed is 300 ÷ 25 = 12 m/s. To solve for distance, multiply speed by time; to solve for time, divide distance by speed.
Speed equals distance divided by time, v = d / t. The rearranged forms are d = v × t and t = d / v. This is the average speed over the whole interval, and it is the speed formula this calculator applies.
The SI unit of speed is the metre per second (m/s). Everyday units are km/h and mph, with ft/s and knots used in engineering and maritime work. One m/s equals 3.6 km/h and 2.237 mph.
Speed is a scalar that reports how fast an object moves; velocity is a vector that also carries direction. Both use v = d / t, but velocity uses displacement, so a closed loop can have positive speed and zero velocity.
Average speed is total distance divided by total time. It is the number a trip planner or a machine-cycle estimate uses, and it is what this calculator returns. Instantaneous speed, the reading on a speedometer, is the speed at one instant.
Divide by 3.6. A 36 km/h speed is 10 m/s, and a 72 km/h speed is 20 m/s. To convert the other way, multiply m/s by 3.6.
Multiply by 1.60934. A 60 mph speed is 96.56 km/h, and a 100 km/h speed is 62.1 mph. For m/s, divide mph by 2.23694.
Divide the distance by the average speed: t = d / v. At 60 mph, 120 miles takes 2 hours. This calculator returns the time in hours, minutes, and seconds when time is the solved value.
Multiply the speed by the time: d = v × t. At 8 m/s for 10 minutes, the distance is 8 × 600 = 4,800 m, or 4.8 km.
Speed is how fast something moves; acceleration is how fast speed changes, in m/s². A constant speed has zero acceleration, while acceleration changes speed over time.
Cutting speed is the rate at which the cutting edge moves through the part surface, in m/min or SFM, and it sets spindle RPM. It is a different quantity from linear speed, and the cutting speed calculator owns it.
Linear speed is distance along a line divided by time. Rotational speed is turns or angular change over time, usually reported as RPM. They connect through the geometry of a wheel or gear, which is where the gear ratio calculator picks up.
PRECISION MANUFACTURING SUPPORT
From Speed Spec to Machined Part
This speed calculator tells you how fast a part moves, or the distance it covers — now you need the part that carries it. Whether it is a conveyor roller, a linear axis bracket, an actuator rod, or a cam profile, the next step is the same: machine the geometry so it matches the number.
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5‑axis CNC machining to ±0.001″
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50+ metals & plastics, ISO 9001 & AS9100
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Free DFM feedback on every quote