Case 1
- Launch speed
- 20m/s
- Launch angle
- 45°
- Gravity
- 9.81m/s²
2.883s
Open with these valuesProjectile Time of Flight Calculator
Change any value to update the result.
2.883s
Time of flight: 2.883 sExamples
How the result moves
Gravity (m/s²) → Time of flight (s)Your current valid inputs, with one value varied across the range.
How the result moves
Held fixed: Launch speed 20.00 m/s, Launch angle 45.00 °.
| Gravity (m/s²) | Time of flight (s) |
|---|---|
| 8.00000 | 3.536 |
| 9.81000Your value | 2.883 |
| 10.00000 | 2.828 |
| 12.00000 | 2.357 |
Only the vertical part of the launch speed keeps a projectile up, so the flight lasts 2 × v × sin θ ÷ g. At 20 m/s and 45° on Earth that is 2.883 s. Gravity is an input, not a fixed number: set it to 1.62 for the Moon or 3.71 for Mars and the same throw hangs far longer.
Worked examples
Case 2
- Launch speed
- 30m/s
- Launch angle
- 60°
- Gravity
- 9.81m/s²
5.297s
Open with these valuesCase 3
- Launch speed
- 25m/s
- Launch angle
- 45°
- Gravity
- 1.62m/s²
21.824s
Open with these valuesHow it's calculated
t = 2 × v × sin θ ÷ g
- StepEnter the launch speed in metres per second — divide km/h by 3.6.Launch speed=20m/s
- StepEnter the angle above the horizontal, between 0° and 90°.Launch angle=45°
- StepLeave gravity at 9.81 for Earth, or enter the value for another body.Gravity=9.81m/s²
- ResultRead the total time from launch to landing, both at ground level.2.883s
Reference table
| Speed, angle, gravity | Where | Time of flight (s) |
|---|---|---|
| 10, 90, 9.81 | Earth, straight up | 2.039 |
| 20, 45, 9.81 | Earth | 2.883 |
| 50, 30, 9.81 | Earth, fast and flat | 5.097 |
| 30, 60, 9.81 | Earth, steep | 5.297 |
| 25, 45, 1.62 | Moon | 21.824 |
Questions
How do I calculate the time of flight of a projectile?
Multiply twice the launch speed by the sine of the angle and divide by gravity: time = 2 × v × sin θ / g. For a 20 m/s launch at 45° on Earth (g = 9.81), that is 2 × 20 × sin 45° / 9.81 ≈ 2.883 s. The time depends only on the vertical part of the velocity, v·sinθ.
Can I use this for the Moon or other planets?
Yes — just change the gravity value. Earth is 9.81 m/s², the Moon about 1.62, Mars about 3.71, and Jupiter about 24.79. Weaker gravity means a longer time of flight for the same launch, which is why a throw hangs so long on the Moon.
Does the mass of the projectile change the flight time?
No. Mass cancels out of the equations of motion, so a pebble and a cannonball launched at the same speed and angle stay up equally long. Only air resistance, which this model ignores, makes the light one behave differently.
How much of the flight is the way up?
Exactly half. The rise takes v × sin θ / g and the fall takes the same again, because launch and landing are at the same height. The peak of the arc therefore sits at the midpoint of the flight time.
Does this calculator include air resistance?
No. It uses the ideal, drag-free equations, assuming the projectile launches and lands at the same height with gravity as the only force. Real projectiles stay up slightly less long, so treat these results as the no-drag upper bound.