Momentum Calculator
Calculate linear momentum from mass and velocity, mass from momentum and velocity, or velocity from momentum and mass (p = mv), with unit pickers for kg·m/s, g·cm/s, lb·ft/s, slug·ft/s, N·s, and common mass and velocity units.
Input
Any two of momentum, mass and velocity determine the third.
Output
| Quantity | Value | Other units |
|---|---|---|
| No data yet | ||
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/momentum-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"solveFor": "momentum",
"momentum": "20",
"momentumUnit": "kgms",
"mass": "10",
"massUnit": "kg",
"velocity": "2",
"velocityUnit": "ms"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `momentum-calculator` tool (Momentum Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/momentum-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="Momentum Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
The Momentum Calculator solves p = mv — linear momentum, mass, or velocity — pick the quantity you're missing, supply the other two, and it converts between kg·m/s, g·cm/s, lb·ft/s, slug·ft/s, N·s, and the common mass and velocity units along the way.
The formula
p = m × vwhere p is momentum, m is mass, and v is velocity. Rearranged for the other two quantities:
m = p ÷ v
v = p ÷ mHow to use it
- Pick what you want to Solve For — Momentum, Mass, or Velocity.
- Fill in the other two fields, each with its own unit picker: kg·m/s, g·cm/s, lb·ft/s, slug·ft/s, and N·s for momentum; kg, g, mg, lb, oz, metric tons, and US (short) tons for mass; m/s, km/h, mph, ft/s, and knots for velocity.
- The result shows the solved value in every supported unit at once, so you don't need to run the calculator again just to see the same figure in lb·ft/s instead of kg·m/s.
Example
A 10 kg object moving at 2 m/s:
p = m × v = 10 kg × 2 m/s = 20 kg·m/sWhy is momentum a vector, and does this calculator handle direction?
Momentum has both magnitude and direction — two objects with equal mass and speed but opposite directions have equal-magnitude, opposite-sign momentum. This calculator works with magnitude only (the speed × mass figure), which is what most one-off "how much momentum does this have" questions need; for collision problems involving direction, treat the sign separately.
Why is N·s listed as a momentum unit?
Momentum and impulse (force × time) share the same units — a newton-second (N·s) is dimensionally identical to a kilogram-meter-per-second (kg·m/s), since a newton is a kg·m/s². They're offered as separate labels because impulse-momentum problems (e.g. "how much impulse changed this object's momentum") often quote the answer in N·s.
Privacy
All calculations run entirely in your browser. Your figures are never uploaded or stored.