Projectile Range Calculator – Ideal 2D Projectile Motion
Projectile motion is a classic topic in physics: an object is launched with some initial speed and angle under the influence of gravity alone. This Projectile Range Calculator lets you explore that motion interactively, computing horizontal range, time of flight, maximum height and impact speed for a wide range of scenarios.
The calculator assumes ideal projectile motion with no air resistance, constant gravity and a flat landing surface. In the launch-height modes, an initial height above the landing level is included in the equations. These assumptions match most textbook examples and many engineering approximations.
Core Equations of Projectile Motion
The motion is typically decomposed into horizontal and vertical components. With launch speed v, angle θ and gravity g:
- Horizontal velocity: vx = v cos(θ)
- Initial vertical velocity: vy0 = v sin(θ)
- Horizontal position: x(t) = vx t
- Vertical position without launch height: y(t) = vy0 t − ½ g t²
For a projectile that lands at the same height from which it was launched (flat ground), the time of flight T and horizontal range R are:
- Time of flight: T = 2v sin(θ) / g
- Horizontal range: R = v² sin(2θ) / g
- Maximum height: Hmax = v² sin²(θ) / (2g)
Including Launch Height h₀
If the projectile is launched from a height h0 above the landing level, the vertical position becomes:
y(t) = h0 + v sin(θ) t − ½ g t²
Solving y(t) = 0 for the time when it hits the ground gives:
Tflight = (v sin(θ) + √[(v sin(θ))² + 2gh0]) / g
The range is then R = v cos(θ) · Tflight, and the maximum height is h0 plus the additional rise due to the vertical component of the velocity.
How the Multi-Mode Projectile Calculator Works
The calculator is organized into four main computational modes plus a gravity reference tab:
- Flat Ground Range: Level launch and landing heights, ideal for pure textbook problems.
- Range with Launch Height: Adds an initial elevation above the landing level.
- Trajectory Details: Provides a full breakdown of horizontal/vertical components, times and speeds.
- Optimal Angle: Illustrates how launch angle affects range and highlights the maximum range angle.
- Gravity Info: Shows common gravity values and explains how to use presets and custom values.
Unit and Gravity Options
Real projects and homework problems often use different unit systems. To keep things flexible, the calculator:
- Accepts speed in m/s, ft/s, km/h or mph.
- Reports distances in either meters or feet.
- Uses gravity in m/s² with presets for Earth, Moon, Mars and Jupiter.
- Performs all internal calculations in SI units and converts results to your chosen units at the end.
When Does the 45° Rule Apply?
A common rule of thumb is that a 45° launch angle maximizes range. This is true when:
- The projectile is launched and lands at the same height.
- There is no air resistance.
- Gravity is constant.
When the launch height is non-zero, or when air resistance is significant, the best angle shifts away from 45°. The optimal-angle tab focuses on the ideal flat-ground case and shows how range changes for several sample angles.
How to Use the Projectile Range Calculator Effectively
- Start in the Flat Ground Range tab to understand basic relationships.
- Switch to Range with Launch Height when your starting point is above the landing level.
- Use the Trajectory Details tab to see components and impact properties for deeper analysis.
- Experiment with the Optimal Angle tab to see how sensitive range is to angle changes.
- Use the Gravity presets to explore how motion differs on the Moon, Mars or Jupiter.
For classroom work, this calculator helps visualize formulas and double-check hand calculations. For engineering, sports and basic planning, it offers a quick way to obtain idealized estimates before considering more complex effects like drag and spin.
Related Physics & Engineering Tools on MyTimeCalculator
Explore more tools that complement projectile motion analysis:
- Reynolds Number Calculator
- Horsepower to Amps Calculator
- Wind Speed to Beaufort Scale Calculator
- Heat Index Calculator
Projectile Motion FAQs
Frequently Asked Questions About Projectile Range
Clear answers to common questions about range, height and time of flight.
Ideal projectile motion without air resistance leads to clean analytical formulas and fast calculations. Once drag is included, the equations become more complex and often require numerical methods. For education and quick estimates, the idealized model is usually sufficient and matches most textbook examples.
Yes. At 90° the range becomes essentially zero and the motion is purely vertical; the calculator focuses on time of flight and maximum height in that case. At very low angles, the range stays finite but maximum height is small. The formulas smoothly handle intermediate angles as well.
The calculator checks for non-positive gravity values and prevents the calculation, since the formulas are only meaningful when gravity is positive. Make sure to use realistic values for g, such as 9.8 m/s² on Earth or the presets for other celestial bodies.