Skip to content
OneKitly
Sign up · Sign in

Speed of sound calculator

How fast sound travels — through air at a given temperature (c ≈ 331.3·√(1+T/273.15) m/s, a touch faster in humid air), or through another medium from a reference table (water ~1481 m/s, steel ~5960 m/s). Results in m/s, km/h and mph, with the Mach-1 reference.

Related tools

All Physics tools →
Wave speed calculatorCompute wave speed from frequency and wavelength (v = fλ).Kinetic energy chicken cookerA famous physics joke, made calculable: could you cook a chicken by throwing it? Each throw deposits kinetic energy ½mv²; cooking it needs enough heat to raise it to 74 °C (Q = m·c·ΔT). It reports the energy per throw and how many throws — at your chosen speed — the meal would take.Penny drop impact calculatorWould a penny dropped from a skyscraper really kill someone? This tool applies quadratic air drag to find the terminal velocity a coin actually reaches, its true impact speed after any fall height, and the kinetic energy — debunking the famous myth with physics.Heat transfer rate calculatorThe rate of heat flow by any of the three mechanisms: conduction through a wall (Q = k·A·ΔT/d), convection from a surface (Q = h·A·ΔT), or radiation between bodies (Q = ε·σ·A·(T₁⁴ − T₂⁴), with temperatures in kelvin). Pick a mode; only its fields matter.Falling through the Earth calculator (gravity tunnel)Jump into a frictionless tunnel bored through the Earth — how long to reach the other side? For a uniform Earth the motion is simple harmonic, so any straight chord takes the same ~42 minutes one way, with a peak speed of ~7.9 km/s through the centre. Switch to the PREM density model for the realistic ~38-minute figure.Banana radiation (equivalent dose) calculatorPut any radiation dose in perspective with the Banana Equivalent Dose — the tiny ~0.1 µSv you get from the potassium-40 in one banana. Enter a dose in µSv, mSv, Sv, mrem or rem and it converts to bananas, standard units and a plain-language risk band.Bernoulli equation calculatorBernoulli's principle for an ideal fluid: pressure + kinetic + potential head stays constant along a streamline, P + ½ρv² + ρgh = constant. Give the conditions at two points and leave one unknown — pressure, velocity or elevation — and it solves for it, revealing how a pipe that narrows speeds the flow and drops the pressure.Buoyancy calculatorWill it float or sink? Archimedes' principle: the buoyant force equals the weight of the displaced fluid, F = ρ·V·g. From the fluid density, the object's volume and mass, it computes the buoyant force, the weight, the net force, the object's density, the float/sink verdict and — if it floats — the fraction that sits below the surface.

Need Speed (m/s), Speed (km/h), Speed (mph)? The Speed of sound calculator derives it from Medium, Air temperature (°C), Relative humidity (%, air) in one step. For instance, with Medium = Air (by temperature), Air temperature (°C) = 20 and Relative humidity (%, air) = 0 it returns Speed (m/s) = 343.215, Speed (km/h) = 1,236 and Speed (mph) = 767.749.

How to use it

  1. Enter your values: Medium, Air temperature (°C), Relative humidity (%, air).
  2. Read the result instantly: Speed (m/s), Speed (km/h), Speed (mph).

Frequently asked questions

How does the Speed of sound calculator work?

It takes Medium, Air temperature (°C) and Relative humidity (%, air) and derives Speed (m/s), Speed (km/h) and Speed (mph) from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

3 values: Medium, Air temperature (°C) and Relative humidity (%, air). Nothing else is required — no account, no file upload.

What does a typical calculation look like?

With Medium = Air (by temperature), Air temperature (°C) = 20 and Relative humidity (%, air) = 0, the calculator returns Speed (m/s) = 343.215, Speed (km/h) = 1,236 and Speed (mph) = 767.749. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

How much does the result change with different inputs?

It moves a lot. Using Medium = Fresh water, Air temperature (°C) = 40 and Relative humidity (%, air) = 5 instead, Speed (m/s) goes from 343.215 to 1,481 — which is why it is worth testing a few scenarios rather than trusting a single figure.

Which “Medium” option should I choose?

You can pick between « Air (by temperature) », « Fresh water », « Sea water », « Steel », « Aluminium » and « Glass ». Each one changes what the calculator works out, so switch and compare — the default is « Air (by temperature) ».

What does it give for smaller values?

Scaled down to Medium = Air (by temperature), Air temperature (°C) = 10 and Relative humidity (%, air) = 1, Speed (m/s) comes out at 337.312. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Checking a homework answer, sizing something before building it, and getting an order of magnitude before committing to a design — a torque on a bolt, the force a spring returns, the frequency a circuit resonates at, how long light takes to arrive.

What is the most common mistake?

Feeding in a value in the wrong unit. Physics formulas assume SI throughout, so grams instead of kilograms or centimetres instead of metres shifts the answer by powers of ten without any warning.

What is the difference between the Speed of sound calculator and the Wave speed calculator?

This one returns Speed (m/s) and Speed (km/h); the Wave speed calculator returns Wave speed (m/s). That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Kinetic energy chicken cooker is the closest one after this: A famous physics joke, made calculable: could you cook a chicken by throwing it? Each throw deposits kinetic energy ½mv²; cooking it needs enough heat to raise it to 74 °C (Q = m·c·ΔT). It reports the energy per throw and how many throws — at your chosen speed — the meal would take.

Further reading

All guides →
ExplainerSound Travels Faster in Steel Because of Stiffness, Not Density343 m/s in air at 20 °C, 1,481 in water, 5,960 in steel and 12,000 in diamond. Steel is 6,500 times denser than air and carries sound only 17 times faster — density slows sound down.ExplainerHow the Doppler Effect Works: The Formula, the Sign Convention, and Why Moving the Source Is Not the Same as Moving the ListenerFor sound, f' = f(v + v_o)/(v − v_s) — and getting the signs backwards is the classic error. Here is the convention spelled out, a 440 Hz source computed at four speeds, and why light needs a different equation entirely.ExplainerA Party Balloon Lifts Fourteen Grams, Not Its Own VolumeA 28 cm latex balloon nets 14 g of lift, so a kilogram takes 72 of them. At 2,000 metres the same balloon lifts 21 % less and you need 91.ExplainerThe Pendulum That Beats Seconds Is Not One Metre LongA one-metre pendulum swings in 2.0061 seconds, not 2. Getting to exactly two takes 0.994 m — and quadrupling the length only doubles the period.ExplainerEvery Major Third on a Piano Is Fourteen Cents SharpThree semitones above A4 is 440 × 2^(3/12) = 523.25 Hz. The twelfth root of two makes every interval slightly wrong except the octave, and that compromise is what lets a keyboard play in any key.ExplainerWhat Is the Reynolds Number? The Formula, the Units That Cancel, and Why 2 300 Is Only for PipesRe = ρvL/μ compares inertia with viscosity, and the units really do cancel. See the number worked out for honey, a household pipe, an artery, a swimmer and a wing — and why the 2 300 threshold belongs to pipe flow alone.