Torque Converter — N·m, lb-ft, lb-in & more

A torque converter is a small utility with an outsized job: it stops a single misplaced decimal or a mixed-up unit from turning into a stripped bolt, a snapped lug nut, or a mechanic's report that nobody can double-check. Torque numbers show up in car spec sheets, service manuals, textbooks, and torque wrench dials in at least six different units, and they rarely match the unit you actually need at the moment you need it.

This page gives you a fast, accurate way to move between newton-metres, kilonewton-metres, pound-feet, pound-inches, kilogram-force-metres, and ounce-inches without reaching for a calculator or trying to remember a conversion constant from memory. At Arb Digital we build tools like this one because we use them ourselves, and we keep them free, ad-supported, and running entirely client-side so anyone — a home mechanic, a machinist, a student, or an engineer double-checking a spec — can use it without friction.

What This Torque Converter Does

Enter any numeric torque value, pick the unit it's currently expressed in, pick the unit you want to see it in, and the converter does the arithmetic instantly. Behind the scenes it converts your input into newton-metres (the SI base unit for torque) and then converts that intermediate value into whatever target unit you selected. Because every unit routes through the same base, the math stays consistent no matter which pair of units you choose, and the quick-reference panel below the main result shows the same value expressed in four other common units at a glance, so you don't have to run the conversion five separate times.

This matters more than it might seem at first glance. Torque specifications show up across wildly different fields — automotive repair, structural engineering, aerospace fastener callouts, physics coursework, and industrial machinery manuals — and each field tends to gravitate toward its own preferred unit out of habit or regional convention. A mechanic trained on American service manuals reaches for pound-feet by reflex; a European or Asian manufacturer's documentation defaults to newton-metres; a machinist working on delicate instrumentation may only ever see ounce-inches or pound-inches. When those worlds collide, as they do whenever an imported part, a translated manual, or an international parts catalog enters the picture, having one reliable place to bridge the units saves real time and prevents real mistakes.

How to Use It

1. Enter your value. Type the torque number you already have — from a spec sheet, a wrench reading, or a textbook problem — into the Value field.
2. Choose the "From" unit. Select whichever unit that number is currently expressed in, such as lb-ft or N·m.
3. Choose the "To" unit. Select the unit you want the result converted into.
4. Read the result. The converted value appears instantly in the result panel, along with four other unit equivalents underneath it.
5. Swap if needed. Use the Swap Units button to instantly reverse the From and To selections without retyping anything.

The Formula / How It's Calculated

Torque is the rotational equivalent of force. Where force describes a straight-line push or pull, torque describes a twisting effort, and it's calculated as force multiplied by the perpendicular distance from the pivot point to where that force is applied — often called the moment arm or lever arm. Double the length of the wrench handle at the same hand force, and you double the torque delivered to the bolt. That relationship, torque = force × distance, is why torque is expressed in compound units like newton-metres or pound-feet: a unit of force multiplied by a unit of length.

Newton-metres (N·m) are the SI-derived unit for torque because they combine the SI unit of force (the newton) with the SI unit of distance (the metre). Every other unit in this converter — pound-feet, pound-inches, kilogram-force-metres, ounce-inches, and kilonewton-metres — is defined relative to that same newton-metre baseline, which is exactly what lets this tool convert between all of them through one consistent intermediate step.

One subtlety worth understanding: torque and energy share the same dimensional units (force × distance), so a newton-metre of torque and a joule of energy are numerically identical, yet they describe completely different physical concepts. Energy is a scalar quantity that represents work done or capacity to do work; torque is a vector-like quantity describing a rotational tendency around an axis. Because of that conceptual difference, engineers deliberately keep the units labeled differently in practice — joules for energy, newton-metres for torque — even though the underlying dimensions match. For a deeper technical reference on SI base and derived units, the NIST guide to SI units is a solid, authoritative starting point.

Torque in Cars and Engines

Automakers publish torque figures right alongside horsepower on every spec sheet, and the two numbers answer different questions. Horsepower tells you how quickly work can be done over time; torque tells you how hard the engine can twist the drivetrain at a given moment, which is why torque correlates more directly with how a vehicle feels off the line and how well it hauls a trailer up a grade. In the United States, engine torque is almost always listed in pound-feet (lb-ft); most of the rest of the world lists the same specification in newton-metres (N·m), which is why a converter that handles both is genuinely useful when comparing a US spec sheet to an international one.

As a rough illustration only — not a universal rule, since every engine and drivetrain is different — a compact sedan with a modest four-cylinder engine might produce somewhere in the neighborhood of 150 to 180 lb-ft of torque, a mid-size performance sedan or crossover might land in the 250 to 350 lb-ft range, and a heavy-duty pickup truck built for towing can reach 400, 500, or even beyond 1,000 lb-ft in diesel configurations. Electric vehicles complicate the comparison further because electric motors deliver near-maximum torque from a full stop, often listed in the 250 to 400+ lb-ft range even in comparatively modest EVs, which is part of why electric cars can feel far quicker off the line than their horsepower figure alone would suggest. None of these figures are guarantees for any specific model — always check the manufacturer's actual published specification for the vehicle in question.

Torque in Bolts and Fasteners

Away from the engine bay, torque specifications govern something just as important: how tightly a bolt, screw, or lug nut is fastened. Manufacturers publish exact torque values in service manuals for a reason — a bolt that's under-tightened can loosen under vibration and fail entirely, while a bolt that's over-tightened can stretch past its yield point, strip its threads, or snap outright, sometimes without any visible warning beforehand. Lug nuts on a passenger vehicle wheel, for example, typically carry a specified torque somewhere between 80 and 100 lb-ft, and that number is chosen precisely, not casually — deviating meaningfully in either direction can create a genuine safety issue.

Because fastener sizes range so widely, torque specs for small fasteners are frequently given in pound-inches (lb-in) rather than pound-feet, since a tiny screw or electronics enclosure fastener might only need a torque value in the single digits when measured in pound-feet, which is awkward to read precisely on a standard wrench. Expressing that same spec in pound-inches — remembering that 1 lb-ft equals 12 lb-in — gives a more readable, more precise number for small-fastener work. A calibrated torque wrench, checked periodically against a known reference, is the only reliable way to hit these specifications consistently; a wrench that's drifted out of calibration can silently apply the wrong torque even when its dial or click point looks correct.

Bolt torque specs also account for factors that aren't obvious from the number alone: the grade or strength class of the bolt, the thread pitch, whether the threads are dry or lubricated, and the material being fastened all influence how much torque is appropriate for a given joint. Two bolts that look identical in size can carry very different torque ratings if they're made from different alloys or heat-treated to different hardness grades, which is exactly why service manuals specify torque per fastener location rather than offering one blanket number for an entire assembly. Following the documented value — not an estimate based on a similar-looking bolt elsewhere — is the safest approach whenever precision genuinely matters.

Common Mistakes to Avoid

• Confusing lb-ft with lb-in. These two units differ by a factor of 12, so mixing them up on a fastener spec can mean applying twelve times too much or too little torque.
• Treating torque and horsepower as interchangeable. They measure different things — twisting force versus the rate of doing work — and a high-torque engine isn't automatically a high-horsepower one, or vice versa.
• Using an uncalibrated torque wrench. Click-type wrenches drift out of calibration over time and with heavy use; check yours periodically against a trusted reference if precision matters.
• Mixing kgf·m and N·m without converting. These values are close in magnitude but not identical (1 kgf·m ≈ 9.807 N·m), and assuming they're interchangeable introduces a small but real error.
• Guessing lug nut or bolt torque instead of checking the manual. Manufacturer-specified torque values account for the specific bolt grade, thread pitch, and material involved — a generic "tight enough" approach isn't a safe substitute.
• Rounding intermediate results too aggressively. When converting through several unit steps by hand, early rounding can compound into a meaningfully wrong final figure; this converter avoids that by computing through a single unrounded base-unit step.

Related Free Tools From Arb Digital

If you found this torque converter useful, several sibling calculators cover other common engineering and physics conversions. Check out our Angle Converter for degrees, radians, and gradians; the Density Converter for material and fluid density comparisons; the Frequency Converter for hertz and related units; the Force Converter for newtons, pounds-force, and dynes; and the Power Converter for watts, horsepower, and BTU per hour. All of these, along with dozens of other calculators, live in our free online tools hub.

Frequently Asked Questions

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