Force, Torque & Mechanical Converters
Mathematically verified calculation engines across linear force units (newtons, kilonewtons, decanewtons, gram-force, kilogram-force, pounds-force), rotational torque moments (newton-meters, foot-pounds, inch-pounds, kilogram-force centimeters), torque-to-horsepower rotational power, line loads, geotechnical specific weight, and gravitational mass equivalence. Strictly adhering to BIPM SI standards, NIST SP 811, and ISO 80000-4.
Nm to Ft Lb Converter — Newton Meters to Foot-Pounds Torque
Essential Mechanical Tools
Nm to Ft Lb Converter
Newtons to Lbs Converter
Inch Lbs to Nm Converter
Torque to Horsepower Converter
Kilonewton to Pound Force Converter
Newton Meter Calculator
Inch Pounds to Foot Pounds Converter
Lb/ft³ to kN/m³ Converter
All 25 Force, Torque & Mechanical Tools
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Group A — Torque & Moment Converters (N·m, ft·lb, in·lb, N·cm, kgf·cm, Lever Arm)
9 itemsGroup B — Force Unit Converters (N, kN, daN, gf, kgf, lbf)
6 itemsGroup C — Torque to Horsepower & Rotational Power (τ & RPM to HP/kW)
1 itemsGroup D — Force per Length & Geotechnical Specific Weight (N/cm, lbf/in, pcf to kN/m³)
3 itemsGroup E — Ambiguous, Prefix & Context-Dependent Calculators (Nm to m, Ton to kN, PN to tonf, Mass Equivalence)
6 itemsWhat are Force & Torque? Physical Foundations & SI Unit Standards
In classical mechanics, force ($\vec{F}$) is any physical interaction that, when unopposed, changes the motion of an object. Force imparts linear acceleration to an object with mass, as described by Newton's second law:
The SI unit of force is the newton (N), defined as the force required to accelerate one kilogram of mass at one meter per second squared ($1\text{ N} \equiv 1\text{ kg}\cdot\text{m}\cdot\text{s}^{-2}$).
Torque ($\vec{\tau}$), also referred to as the moment of force, represents the rotational analog of linear force. It measures the tendency of a force to rotate an object about an axis, pivot, or fulcrum:
Why Torque Must Never Be Expressed in Joules: While torque shares the base dimensional formula $[M L^2 T^{-2}]$ with mechanical work and energy (1 J = 1 N·m), ISO 80000-4 and the BIPM SI Brochure strictly mandate that torque be expressed only in newton-meters (N·m) and never in joules. Torque is a rotational pseudovector resulting from an exterior vector cross product ($\vec{r} \times \vec{F}$), whereas work is a scalar quantity resulting from an inner dot product ($\vec{F} \cdot \vec{d}$).
Comprehensive Force & Torque Unit Reference Guide
| Unit Name | Symbol | Quantity | Exact SI Equivalence | Primary Domain |
|---|---|---|---|---|
| Newton | N | Force | $1\text{ N} \equiv 1\text{ kg}\cdot\text{m/s}^2$ | SI Base Standard |
| Kilonewton | kN | Force | $1,000\text{ N}$ | Structural Engineering, Rigging |
| Decanewton | daN | Force | $10\text{ N}$ | European Cargo Lashing (EN 12195) |
| Pound-Force | lbf | Force | $\approx 4.448222\text{ N}$ | US Customary Machinery |
| Kilogram-Force | kgf / kp | Force | $9.80665\text{ N}$ | Legacy Metric Technical Standards |
| Newton-Meter | N·m | Torque | $1\text{ N}\cdot\text{m}$ | SI Torque Benchmark |
| Foot-Pound Force | ft·lbf | Torque | $\approx 1.355818\text{ N}\cdot\text{m}$ | Automotive Engine Output |
| Inch-Pound Force | in·lbf | Torque | $\approx 0.112985\text{ N}\cdot\text{m}$ | Bicycle, Firearms, Electronics |
| Kilogram-Force cm | kgf·cm | Torque | $0.0980665\text{ N}\cdot\text{m}$ | RC Servos, Stepper Motors |
Torque to Horsepower: How Shaft Speed Generates Mechanical Power
A common saying in automotive engineering states: "Torque is how hard you hit the wall; horsepower is how fast you hit it." Physically, torque ($\tau$) represents rotational work capability per radian, while power ($P$) is the rate at which that work is delivered over time:
The Origin of the 5,252 Constant: In imperial units, James Watt defined one mechanical horsepower as $33,000\text{ ft}\cdot\text{lbf/min}$ ($550\text{ ft}\cdot\text{lbf/s}$). Substituting angular velocity into Watt's formula yields:
Because of this exact mathematical derivation, on any imperial chassis dyno graph plotting torque in foot-pounds and power in horsepower against engine speed, torque and horsepower curves always intersect at exactly 5,252 RPM. In metric SI, power in kilowatts is calculated via $P (\text{kW}) = \frac{\tau (\text{N}\cdot\text{m}) \cdot \text{RPM}}{9548.8}$.
Frequently Asked Questions
How do I convert newton-meters to foot-pounds? ↓
Multiply newton-meters by $0.737562$ to get foot-pounds ($\text{lbf}\cdot\text{ft}$). Conversely, multiply foot-pounds by $1.355818$ to get newton-meters. Use our Nm to Ft Lb Converter for instant bidirectional calculation.
Why does 1 N/m equal 1 J, but torque cannot be measured in joules? ↓
Torque is an exterior cross product ($\vec{r} \times \vec{F}$), creating a rotational pseudovector. Work and energy are interior dot products ($\vec{F} \cdot \vec{d}$), creating a scalar quantity. ISO 80000-4 and BIPM forbid using joules for torque to prevent confusion between rotational effort and consumed energy.
What is the difference between metric tonne-force, short ton-force, and long ton-force? ↓
Metric tonne-force ($1,000\text{ kg} \times 9.80665\text{ m/s}^2$) equals $9.80665\text{ kN}$. US short ton-force ($2,000\text{ lbf}$) equals $8.89644\text{ kN}$. Imperial long ton-force ($2,240\text{ lbf}$) equals $9.96402\text{ kN}$. Always clarify which ton-force convention applies in crane rigging documents.
How is specific weight related to mass density? ↓
Specific weight ($\gamma$, measured in $\text{kN/m}^3$ or $\text{lbf/ft}^3$) is the gravitational force per unit volume, calculated by multiplying mass density ($\rho$) by local gravitational acceleration: $\gamma = \rho \cdot g$. Under standard Earth gravity, $1\text{ lb/ft}^3 \approx 0.157087\text{ kN/m}^3$.