Free Fall Calculator

Height, time and impact velocity on Earth, Moon or Mars

Quick Answer

Free Fall Calculator: Height, time and impact velocity on Earth, Moon or Mars. v = g·t · h = ½g·t² · t = √(2h/g) · v = √(2gh).

Height (m)

g（m/s²）

Impact speed

29.70 m/s

falls 3.03 s · 107 km/h

Height45.00 m

Time3.030 s

Impact v29.70 m/s

km/h106.9

Steps

1t = √(2h/g) = √(2 × 45 ÷ 9.8) = 3.030 s
2v = gt = 9.8 × 3.030 = 29.70 m/s = 106.9 km/h
3Check: v = √(2gh) = √(2 × 9.8 × 45.00) = 29.70 m/s ✓

Second-by-second fall

t (s)	Distance (m)	Speed (m/s)
1.00	4.90	9.8
2.00	19.60	19.6
3.00	44.10	29.4
3.03	45.00	29.7

💡 Vacuum free fall ignores air resistance — distance grows with t² (1st second 4.9m, 2nd 19.6m, 3rd 44.1m…). In air, terminal velocity caps a skydiver near 55 m/s. The same g lets you estimate a well's depth by timing a dropped stone.

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How to Use

Enter known quantities: fill values and confirm units in the Free Fall Calculator.
Instant solution: unknowns solve live with the formula shown transparently.
Use constant/material tables: standard physical constants and material data are listed on this page.
Compare conditions: change inputs to compare scenarios.

Key Points

Free Fall Calculator is a free online science & engineering tool — open and use, no sign-up.
All calculations run locally in your browser; your data never leaves the device.
Key capability: Height, time and impact velocity on Earth, Moon or Mars.
Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

Free fall (no air resistance)

v = g·t · h = ½g·t² · t = √(2h/g) · v = √(2gh)

g: Earth 9.807, Moon 1.62, Mars 3.71, Jupiter 24.79 m/s²

Reality check: human terminal velocity ≈ 53 m/s

FAQ

How do I use the Free Fall Calculator?

Open the page and fill in the input fields — results update automatically. Height, time and impact velocity on Earth, Moon or Mars.

Are the results accurate?

Yes. Standard formulas and conversion factors are used and verified.

Is it free? Do I need to sign up?

Completely free. No registration, login or download required.

Does it work on mobile?

Yes. The responsive design works on phones, tablets and desktops.

Is my data saved?

No. Everything runs locally in your browser.

Related Guides

Source & Updates

Based on CODATA recommended constants and standard physics formulas. Last updated: 2025-07

Last updated: 2026-08-04

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Cite this page: YiJianSuan. Free Fall Calculator[EB/OL]. https://www.yijiansuan.com/en/c/science/free-fall

Results provided by this tool are for reference only and do not constitute professional advice.