Torque Converter
Convert newton-meters, foot-pounds, pound-inches, and more
💡 Tip: Press Ctrl+D for dark mode, Ctrl+K to focus converter
🔧 Torque Converter
Convert between torque units
Torque Conversion Guide
Common Torque Conversions
| From | To | Multiply by | Example |
|---|---|---|---|
| Newton-meter | Pound-foot | × 0.7376 | 100 Nm = 73.76 lb-ft |
| Pound-foot | Newton-meter | × 1.3558 | 100 lb-ft = 135.58 Nm |
| Newton-meter | Pound-inch | × 8.851 | 10 Nm = 88.51 lb-in |
| Pound-inch | Newton-meter | × 0.113 | 100 lb-in = 11.3 Nm |
| Pound-foot | Pound-inch | × 12 | 10 lb-ft = 120 lb-in |
| Newton-meter | kgf·m | × 0.102 | 100 Nm = 10.2 kgf·m |
| kgf·m | Newton-meter | × 9.807 | 10 kgf·m = 98.07 Nm |
Understanding Torque
What is Torque?
Torque is a rotational force - the "twisting" or "turning" force applied to an object. It's what makes things spin.
Formula: Torque = Force × Distance (τ = F × r)
Example: If you push a wrench handle with 10 N of force at 0.5 meters from the bolt, you create 5 Nm of torque.
Newton-meter (Nm)
The newton-meter is the SI unit of torque. One newton-meter is the torque from 1 newton of force applied at 1 meter from the pivot point.
Common uses: Engine torque specs (50-300 Nm), bolt tightening (5-150 Nm)
Pound-foot (lb-ft)
Pound-foot is commonly used in the United States for automotive applications. One pound-foot is 1 pound of force applied at 1 foot from the pivot.
Example: A typical car engine produces 150-300 lb-ft of torque
Important: lb-ft means pound-feet, not foot-pounds (which has a different meaning in energy)
Pound-inch (lb-in)
Pound-inch is used for smaller fasteners and precision work. 1 lb-ft = 12 lb-in.
Common uses: Small screws, electronics assembly (5-50 lb-in)
Kilogram-force meter (kgf·m)
Kilogram-force meter is an older metric unit still used in some countries. 1 kgf·m = 9.807 Nm.
Note: Being phased out in favor of Nm, but still seen in older service manuals
Torque Examples by Application
| Application | Typical Torque | In Different Units |
|---|---|---|
| Small screw (M3) | 0.5 Nm | 4 lb-in / 0.37 lb-ft |
| Bicycle pedal | 30 Nm | 22 lb-ft / 265 lb-in |
| Car lug nut | 100 Nm | 74 lb-ft / 885 lb-in |
| Spark plug | 20-30 Nm | 15-22 lb-ft |
| Oil drain plug | 25-30 Nm | 18-22 lb-ft |
| Cylinder head bolt | 80-120 Nm | 59-89 lb-ft |
| Compact car engine | 180 Nm | 133 lb-ft (at peak RPM) |
| V8 sports car engine | 500 Nm | 369 lb-ft |
| Semi truck engine | 2000 Nm | 1475 lb-ft |
| Electric car motor | 300-600 Nm | 221-443 lb-ft |
Torque vs. Power
Critical difference:
- 🔧 Torque: Rotational force - how hard the engine can push
- ⚡ Power: Rate of doing work - how fast the engine can work
- 📐 Relationship: Power = Torque × RPM ÷ 5252 (in HP and lb-ft)
- 🚗 Low-end torque: Acceleration from standstill, towing ability
- 🏁 High RPM power: Top speed capability
Example:
- Diesel engine: High torque (400 lb-ft), moderate power (200 HP) → Great for towing
- Sport bike: Moderate torque (70 lb-ft), high power (150 HP) → Great for high-speed acceleration
Torque Wrench Usage
Why torque matters:
- ✅ Too little: Bolts can loosen, parts can separate, gaskets can leak
- ❌ Too much: Threads strip, bolts break, parts crack or warp
- 🎯 Just right: Proper clamping force, even pressure distribution
Common torque wrench types:
- 🔧 Click-type: Makes a "click" when target torque is reached (most common)
- 📏 Beam-type: Simple pointer shows torque value (no calibration needed)
- 💡 Digital: LCD display, often with angle measurement
- 🔔 Electronic: Vibrates/beeps at target torque
Automotive Torque Specifications
| Component | Typical Torque (Nm) | Typical Torque (lb-ft) |
|---|---|---|
| Spark plugs | 20-30 | 15-22 |
| Oil drain plug | 25-30 | 18-22 |
| Oil filter | 15-25 | 11-18 |
| Wheel lug nuts (car) | 100-120 | 74-89 |
| Wheel lug nuts (SUV) | 120-150 | 89-111 |
| Caliper bracket bolts | 80-120 | 59-89 |
| Cylinder head bolts | 80-120 | 59-89 |
| Crankshaft bolt | 150-250 | 111-184 |
| Axle nut | 200-250 | 148-184 |
⚠️ Important: Always consult your vehicle's service manual for exact specifications. These are general ranges only.
Torque in Engineering
Tightening Sequence
For multi-bolt patterns (like cylinder heads or wheels):
- 1️⃣ Pattern: Tighten in a criss-cross or star pattern
- 2️⃣ Stages: Often done in 2-3 stages (e.g., 50%, 80%, 100%)
- 3️⃣ Final pass: Return to first bolt and verify all torques
- 🔄 Angle torque: Some bolts use torque + angle (e.g., 50 Nm + 90°)
Torque-to-Yield Bolts
TTY bolts are tightened beyond their elastic limit and must be replaced after removal:
- Used on cylinder heads, connecting rods, main caps
- Tightened to specific torque, then rotated additional degrees
- Provide more consistent clamping force
- ❌ Never reuse - they permanently stretch
Electric vs. Combustion Engine Torque
| Type | Torque Delivery | Advantages |
|---|---|---|
| Gasoline Engine | Peak at 4000-6000 RPM | High top speed, familiar |
| Diesel Engine | Peak at 2000-3000 RPM | Better fuel economy, towing |
| Electric Motor | Max torque from 0 RPM | Instant acceleration, simple |
| Hybrid | Combined electric + gas | Best of both worlds |
Why electric cars feel so quick: Full torque available instantly, no waiting for RPM to build up!
Preventing Fastener Failure
- 🔧 Clean threads: Dirt/corrosion changes friction, affects torque accuracy
- 💧 Lubrication matters: Dry vs. oiled threads require different torque values
- 🆕 Use new washers: Crushed washers don't compress properly
- 📏 Calibrate tools: Torque wrenches should be calibrated yearly
- ⚠️ Never extend handles: Using a pipe on wrench handle = over-torque
- 🔄 Replace worn fasteners: Stripped threads can't hold proper torque
Frequently Asked Questions
How do I convert Nm to lb-ft?
Multiply newton-meters by 0.7376. Example: 100 Nm × 0.7376 = 73.76 lb-ft. To go the other way, multiply lb-ft by 1.3558.
What's the difference between torque and horsepower?
Torque is rotational force (how hard the engine can push). Horsepower is the rate of doing work (how fast it can push). Formula: HP = (Torque × RPM) ÷ 5252. High torque = better acceleration. High horsepower = better top speed.
How tight should I torque my lug nuts?
Typical car lug nuts: 80-120 Nm (60-90 lb-ft). SUV/Truck: 120-150 Nm (90-110 lb-ft). Always check your owner's manual for exact specs. Use a torque wrench - over-tightening can warp brake rotors and damage studs.
Can I use a regular wrench instead of a torque wrench?
Not recommended for critical fasteners. Regular wrenches can't measure torque accurately. Use a torque wrench for: wheel lug nuts, cylinder heads, spark plugs, oil drain plugs, and any bolt with a specified torque value. You'll save money avoiding broken bolts and warped parts.
What is lb-ft vs. ft-lb?
lb-ft (pound-foot) is torque - rotational force. ft-lb (foot-pound) is energy/work. They're numerically equal but represent different concepts. For torque, always use lb-ft (or better: Nm).
Why do electric cars have so much torque?
Electric motors deliver maximum torque instantly from 0 RPM. Gas engines need to "rev up" to reach peak torque (typically 3000-5000 RPM). This is why electric cars feel so quick off the line, even if their horsepower isn't that high.
How do I calculate torque?
Formula: Torque = Force × Distance. Example: You push a 1-foot wrench with 50 pounds of force = 50 lb-ft of torque. Or: 100 N force at 0.3 meters = 30 Nm of torque.
Torque Conversion Formulas
Quick reference:
- Nm to lb-ft: Nm × 0.7376
- lb-ft to Nm: lb-ft × 1.3558
- Nm to lb-in: Nm × 8.851
- lb-in to Nm: lb-in × 0.113
- lb-ft to lb-in: lb-ft × 12
- lb-in to lb-ft: lb-in ÷ 12
- kgf·m to Nm: kgf·m × 9.807
- Nm to kgf·m: Nm × 0.102