How torque unit conversion works

Every torque unit is just a different way to express the same physical idea: a force applied at a distance from a pivot. Converting units is therefore a two-step “language translation”:

• Step 1: Convert your input into a base unit (we use N·m as the base).
• Step 2: Convert from the base unit into your target unit.

This converter treats N·m as the “hub” unit because it’s the SI standard and makes the math tidy. Internally we store a conversion factor that answers: “How many N·m is 1 unit?” Then any conversion becomes:

value_in_target = value × (N·m per fromUnit) ÷ (N·m per toUnit)

Common torque units (what they mean)

• N·m (Newton‑meter): Newtons of force applied at a 1‑meter lever arm.
• lb‑ft (pound‑foot): pounds‑force applied at a 1‑foot lever arm.
• lb‑in (pound‑inch): same idea, but using inches instead of feet — useful for smaller fasteners.
• kgf·m / kgf·cm: based on kilogram‑force (a legacy gravitational unit). You’ll see this in some manuals and older tools.
• N·cm: same as N·m, but scaled by 100 for small torques (common in electronics).
• dyn·cm: a CGS unit; appears in physics and some niche engineering references.

Why “N·m” sometimes looks like “Joule”

A fun physics detail: 1 N·m has the same dimensions as 1 Joule (because both equal a Newton times a meter). The difference is context. A Joule is energy (work done). A Newton‑meter in torque is a twisting effect. Same units on paper — different meaning in the real world.

Real-world torque conversion examples

Examples make this feel less like “unit soup.” Here are a few common situations where a torque converter saves time — and prevents mistakes.

Your manual says wheel lugs should be tightened to 90 lb‑ft, but your torque wrench is set in N·m. Convert:
90 lb‑ft × 1.35582 = 122.02 N·m (rounded to 122 N·m).

A spec calls for 72 lb‑in. Many people prefer lb‑ft for a bigger wrench scale. Since 12 lb‑in = 1 lb‑ft, you get:
72 ÷ 12 = 6 lb‑ft.

A hobby motor is rated at 0.45 N·m and you want kgf·cm (common in hobby specs). One easy pathway is N·m → kgf·m → kgf·cm:
0.45 N·m ÷ 9.80665 = 0.04587 kgf·m
0.04587 kgf·m × 100 = 4.587 kgf·cm (≈ 4.59 kgf·cm).

A great habit is to convert forward and then back. If the number returns to (roughly) your starting value, you’ve likely selected the right units. This is especially helpful when you’re switching between lb‑ft and lb‑in, where a factor of 12 can cause big mistakes.

What this page calculates (and what it doesn’t)

This tool converts torque units only. It does not compute torque from force and distance unless you already know one of them. If you want to compute torque from a wrench length and applied force, you can use the core physics relationship: τ = F × r.

• Force pushes in a straight line (Newtons, pounds-force).
• Torque twists around a point (N·m, lb‑ft).
• Same force can create different torque depending on lever arm length.

The calculator displays a clean rounded output for readability, plus a higher‑precision value in the “details” line. For critical work, always follow the exact manufacturer spec and use a calibrated tool.

We format the result so it’s easy to screenshot and share (and we include one‑tap share buttons). The goal is simple: if someone posts a torque spec screenshot, your converter result can be the second screenshot in the thread.

Frequently Asked Questions

• What’s the difference between lb‑ft and lb‑in?

  They are the same unit system, just different scale. 1 lb‑ft = 12 lb‑in. Use lb‑in for smaller torques (electronics, small bolts) and lb‑ft for larger torques (wheels, suspension, engines).

• Why do some manuals use kgf·m or kgf·cm?

  Those units are based on kilogram‑force (a gravitational unit). They’re common in older documentation and certain regions/industries. The conversion is straightforward because 1 kgf = 9.80665 N.

• Is “N·m” the same as Joules?

  Numerically they share the same base units (Newton × meter), but they represent different physical concepts depending on context: torque (rotation tendency) vs energy (work). In torque problems, treat N·m as torque.

• How accurate is this converter?

  It uses standard unit relationships and is accurate to typical floating‑point precision. For safety‑critical applications, you should still use the correct torque procedure, proper lubrication assumptions, and calibrated tools.

• Can I convert “N·m” to “ft‑lb” (same thing as lb‑ft)?

  Yes — “ft‑lb” and “lb‑ft” are used interchangeably in everyday talk, but to avoid confusion with energy units (ft‑lb of work), many torque charts write lb‑ft. This converter uses lb‑ft labeling for clarity.

• What’s a quick mental estimate for N·m ↔ lb‑ft?

  A handy approximation: 1 N·m ≈ 0.74 lb‑ft and 1 lb‑ft ≈ 1.36 N·m. For quick checks it’s fine; for real specs, use the calculator.

• Does torque change if I use a longer wrench?

  The torque you apply depends on force and lever arm length (τ = F × r). A longer wrench makes it easier to achieve the same torque because you need less force — but the torque spec itself doesn’t change.