Enter a horsepower value (or turtle power value) and pick the unit — the calculator converts between horsepower and Turtle Power (TP), where 1 TP is defined as 0.25 watts, a rough stand-in for the sustained power output of an average adult turtle.

HP → Turtle Power
Turtle Power → HP
Enter horsepower to see it in turtle power units.
Enter a positive number.
Enter turtle power to see it in horsepower.
Enter a positive number.
How this is calculated
Copy result

Related Calculators

Formula

The conversion goes through watts as a common unit.

Horsepower → Turtle Power:
TP = (HP × WHP) ÷ 0.25
where TP = turtle power, HP = horsepower value entered, WHP = watts per horsepower unit (745.7 for mechanical HP, 735.5 for metric PS, 746 for electrical HP, 9809.5 for boiler HP).

Turtle Power → Horsepower:
HP = (TP × 0.25) ÷ WHP
where 1 TP ≡ 0.25 W.

Interpretation

The result tells you how many average turtles — working in parallel at their sustained metabolic output — it would take to match the input power. Because 1 HP is roughly 746 W and 1 TP is 0.25 W, every 1 HP works out to about 2,983 TP. A 200 HP car engine lands near 596,600 TP, and a 1 HP household motor is near 2,983 TP.

  • < 1 TP: less than a single slow turtle.
  • 1–100 TP: a small huddle to a pond’s worth.
  • 100–10,000 TP: a small army up to a nesting beach.
  • > 100,000 TP: a turtle population the size of a small city.

Conversion Reference

HorsepowerWattsTurtle Power (TP)
0.1 HP74.6 W298
1 HP745.7 W2,983
10 HP7,457 W29,828
100 HP74,570 W298,280
500 HP372,850 W1,491,400

FAQ

Is turtle power a real scientific unit?
No. It’s a novelty unit defined here as 0.25 W — a reasonable approximation of a turtle’s sustained metabolic power output, but not a standardized SI unit.

Which horsepower option should I pick?
Use mechanical HP (745.7 W) for engines and most US specs, metric HP / PS (735.5 W) for European car specs, electrical HP (746 W) for motor nameplates, and boiler HP (9,809.5 W) only for steam-boiler ratings.

Why do the same HP numbers give slightly different TP values?
Because each horsepower type converts to a slightly different number of watts. The TP output scales directly with that underlying watt value.

Can I use this for peak/burst power instead of sustained power?
The 0.25 W figure represents sustained output. A turtle can briefly exceed that, so for short-burst comparisons the real-world TP count would be somewhat lower.