Recoil Calculator
🎱 Momentum & collisions. Use the Recoil (explosion from rest) formula to find recoil velocity, gun mass, bullet mass, bullet velocity: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Recoil velocity | m/s |
| Gun mass | kg |
| Bullet mass | kg |
| Bullet velocity | m/s |
Worked example
Find the recoil velocity when Gun mass = 4 kg, Bullet mass = 0.004 kg, Bullet velocity = 400 m/s.
Using m1v1 = -m2v2: Recoil velocity = -0.4 m/s.
Frequently asked questions
What is the formula for Recoil (explosion from rest)?
m1v1 = -m2v2.
What do the letters stand for, and what units are used?
Recoil velocity in m/s, Gun mass in kg, Bullet mass in kg, Bullet velocity in m/s.
How do you calculate recoil velocity?
Put the values into m1v1 = -m2v2. For example, with Gun mass = 4 kg, Bullet mass = 0.004 kg, Bullet velocity = 400 m/s, recoil velocity = -0.4 m/s.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (recoil velocity, gun mass, bullet mass, bullet velocity) and fill in the others: it rearranges the formula for you.
