v = √(2mg/ρACd). Free online Terminal Velocity. Calculate terminal velocity online — fast, accurate, mobile-friendly, no signup needed.
At terminal velocity, drag balances gravity.
v (m/s)
40.020403
Derivation
├── 01Givenm = 70, A = 0.7, Cd = 1, rho = 1.225
├── 02Formula√(2 × t × 9.81 / (r × a × n))
└── 03Compute v (m/s)40.020403
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§01What is
Understanding the Terminal Velocity
The Terminal Velocity computes v (m/s) from 4 inputs: mass (kg), area (m²), drag coeff, density (kg/m³). v = √(2mg/ρACd).
Physics is the toolkit for turning a real-world observation into a prediction. Whether it’s a falling object, a moving car, or a stressed beam, the equations here are the same ones every engineer relies on.
The Terminal Velocity sits in that toolkit — it v = √(2mg/ρACd). Enter your numbers above and the result updates instantly; every step of the math is shown in the Derivation panel so you can see exactly how the answer was reached.
§02The Formula
How it’s calculated
√(2 × t × 9.81 / (r × a × n))
Where
m
Mass (kg)
A
Area (m²)
Cd
Drag coeff
rho
Density (kg/m³)
§03Practical Example
Step-by-step walkthrough
Scenario
Apply the formula to a realistic set of inputs: Mass (kg) = 70, Area (m²) = 0.7, Drag coeff = 1, Density (kg/m³) = 1.225.
01Start by noting the input — Mass (kg): 70.
02Start by noting the input — Area (m²): 0.7.
03Start by noting the input — Drag coeff: 1.
04Start by noting the input — Density (kg/m³): 1.225.
05Substitute these values into the formula: √(2 × t × 9.81 / (r × a × n))
06Compute v (m/s): the calculator returns 40.0204.
07Cross-check the answer by opening the Derivation panel above — every line of math is shown so you can follow the computation end-to-end.
§04Variants
Common Terminal Velocity Problems
The formula gets rearranged depending on which variable you need. Here are the patterns you’ll run into in the real world — find the one that matches your problem and follow the worked steps.
01 · PATTERN
Mass (kg) halved
m = 35 (from 70)
Keep every other input at its default and halve the mass (kg). See how v (m/s) responds.
01New Mass (kg): 35
02Baseline v (m/s): 40.0204
03New v (m/s): 28.2987
04v (m/s) decreases by 29.3% → use this sensitivity to plan for real-world variation.
02 · PATTERN
Mass (kg) doubled
m = 140 (from 70)
Keep every other input at its default and double the mass (kg). See how v (m/s) responds.
01New Mass (kg): 140
02Baseline v (m/s): 40.0204
03New v (m/s): 56.5974
04v (m/s) increases by 41.4% → use this sensitivity to plan for real-world variation.
03 · PATTERN
Area (m²) halved
A = 0.35 (from 0.7)
Keep every other input at its default and halve the area (m²). See how v (m/s) responds.
01New Area (m²): 0.35
02Baseline v (m/s): 40.0204
03New v (m/s): 56.5974
04v (m/s) increases by 41.4% → use this sensitivity to plan for real-world variation.
04 · PATTERN
Area (m²) doubled
A = 1.4 (from 0.7)
Keep every other input at its default and double the area (m²). See how v (m/s) responds.
01New Area (m²): 1.4
02Baseline v (m/s): 40.0204
03New v (m/s): 28.2987
04v (m/s) decreases by 29.3% → use this sensitivity to plan for real-world variation.
§05FAQ
Frequently asked questions
Yes. The calculator implements the standard formula as documented and returns exact floating-point results. No approximations are used unless noted in the formula.
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