| Scenario | Inputs | Output |
|---|---|---|
| 0 to 100 km/h in 8.5 s | v0=0, v1=100 km/h, t=8.5 s | a≈3.27 m/s² (≈0.33 g) |
| 0 to 60 mph in 6.2 s | v0=0, v1=60 mph, t=6.2 s | a≈4.33 m/s² (≈0.44 g) |
| 120 m in 8.5 s from rest | v0=0, s=120 m, t=8.5 s | a≈3.32 m/s²; v1≈28.2 m/s |
| Simulation to 100 km/h | m=1500 kg, power=220 hp, μ=1.0, Cd=0.30, A=2.2 | Time and distance depend on limits and drag |
- Select a calculation method that matches your data.
- Enter values using the correct units in each field.
- For simulation, set mass, power, traction, and drag inputs.
- Click Calculate to view acceleration and timing results.
- Use Download CSV or Download PDF for reports.
Acceleration basics you can compare
Car acceleration is the rate of change of speed. Common benchmarks are 0–60 mph (0–96.6 km/h) or 0–100 km/h times, plus peak acceleration in m/s² or “g” (1 g ≈ 9.81 m/s²). This calculator converts units, too, and can simulate a run to compare setups on the same scale.
From power and mass to acceleration
A quick estimate starts with F = m·a, so a = F/m. If you begin with engine power, the tire force at a given speed is roughly F ≈ (P·η)/v, where η is drivetrain efficiency and v is speed. Power itself relates to torque by P = T·ω, so higher rpm can sustain force as speed rises.
Traction limit at the tires
Tires can only transmit so much grip before slipping. The traction ceiling is Fmax = μ·m·g, where μ is the tire–road friction coefficient. Dry performance tires may be near 0.9–1.2, while wet roads are much lower. The simulator caps acceleration whenever demanded force exceeds Fmax.
Aerodynamic drag grows fast
Drag rises with speed squared: Fd = 0.5·ρ·Cd·A·v². Near sea level, air density ρ is about 1.225 kg/m³. Many modern cars sit around Cd 0.25–0.35, with frontal area A near 2.0–2.4 m². At higher speeds, drag reduces available acceleration sharply. Small Cd improvements matter most above 60–70 mph.
Rolling resistance and road grade
Rolling resistance is modeled as Fr = Crr·m·g, with Crr commonly 0.01–0.02 for passenger tires. Hills add gravity along the slope: Fgrade = m·g·sin(θ). A 5% grade adds about 0.05·m·g uphill, increasing times and reducing peak speed for a fixed distance run.
Gearing and speed windows
Gearing matters because wheel force changes with ratio and engine torque. A short first gear can improve launch but may require a shift before 60 mph. Use the graph to spot where acceleration dips; it often aligns with shifts, traction control, or the growing influence of drag.
Using results for planning and testing
For modifications, change one input at a time: mass, power, μ, Cd, or grade. The speed–time curve shows how quickly speed builds; the acceleration curve reveals launch grip and mid‑range pull. Export CSV for logs and PDF for sharing. Compare runs at the same temperature, tires, and consistent fuel load. Treat results as estimates, then validate with real timing.
1. What inputs give the most realistic results?
Use measured vehicle mass, drivetrain efficiency, tire μ, and an estimated Cd and frontal area. If you know wheel horsepower, enter that instead of crank power. For timing runs, keep grade at 0% unless you are modeling a real hill.
2. Why does acceleration drop as speed increases?
As speed rises, the same power produces less force because F ≈ P/v. Aerodynamic drag also grows with v², and rolling resistance stays roughly constant. Together, they reduce net force, so the acceleration curve naturally tapers off.
3. How do I estimate tire–road friction (μ)?
Start with 0.9 for good dry street tires, 1.1 for performance summer tires on warm asphalt, and 0.6–0.7 for wet conditions. If the car launches with wheelspin, lower μ until the simulated launch matches what you observe.
4. What does the Plotly graph show?
The speed–time trace shows how quickly the car gains speed. The acceleration–time trace highlights launch grip, mid‑range pull, and any dips from shifts or drag. Hover points to read exact values, and zoom to inspect a specific time window.
5. Can I use this for electric vehicles?
Yes. EVs often have strong low‑speed torque, so traction becomes the limiting factor early. Enter vehicle mass, available power, and a realistic μ. You can also adjust efficiency and drag to match the vehicle’s known 0–60 or 0–100 km/h times.
6. How accurate are 0–60 and quarter‑mile estimates?
They are estimates based on simplified physics and your inputs. Real results vary with tire temperature, launch technique, wind, drivetrain limits, and shifting. Use the calculator for comparisons and sensitivity testing, then confirm with timed runs or data logs.