Same input, every torque unit — tap a tile to set the right-hand unit.
Automotive unit converter for metric and imperial specs
Built for shop work — torque, power, pressure, displacement, and speed — not generic kitchen conversions.
Convert one pair for a headline number, or read the full board when a dyno sheet mixes units.
Mechanical hp and metric PS are not identical — this tool keeps them distinct so regional claims stay honest.
Mechanics constantly jump between systems: a US torque wrench in lb·ft against a European service manual in N·m, tire pressure in psi next to a boost gauge in bar, or a crate engine listed as 6.2 L and 376 ci. This converter is meant for those cross-checks — enter the number you have, pick the category, and read every common unit on the board.
Each category also has its own page (power, pressure, displacement, and the rest) so a search for “hp to kW” or “psi to bar” lands on copy written for that job. Use this hub when you are bouncing between categories; use a dedicated page when you want that unit pair in the title.
Treat the readout as a precision aid, not a substitute for OEM torque procedures or legal speed claims. When fastener torque or emissions paperwork is on the line, verify against the manufacturer’s published table after you convert. Displacement badges are rounded; if you have bore, stroke, and cylinder count, use the engine displacement calculator instead of a liters-to-ci shortcut.
Common shop conversions
These are the pairs that show up on the bench. Use the table as a sanity check, then enter your exact figure above — 65 lb·ft is not 70, and a 5.3 L truck mill is not a 350.
Typical automotive unit conversions
Job
Category
You have
You need
Wheel offset ET 35
Length
35 mm
1.38 in
SBC 350 stroke
Length
3.48 in
88.4 mm
Head-bolt spec
Torque
65 lb·ft
88 N·m
Street V8 peak
Torque
400 lb·ft
542 N·m
US 400 hp claim
Power
400 hp
298 kW / 406 PS
Door-sticker PSI
Pressure
32 psi
2.21 bar / 221 kPa
5.7 L badge
Volume
5.7 L
348 ci
Highway indicated
Speed
70 mph
113 km/h
Constants: 1 in = 25.4 mm; 1 lb·ft ≈ 1.356 N·m; 1 hp ≈ 0.746 kW; 1 L ≈ 61.02 ci; 1 psi ≈ 0.06895 bar.
When a dedicated calculator is the better tool
Unit conversion does not tell you whether a 35×12.50R17 clears the fender, what RPM a 4.10 axle makes at 70 mph, or how much injector you need for 500 hp. Those jobs need geometry or a fuel formula — use tire size, RPM at speed, and injector sizing rather than converting a single number and guessing the rest.
How to convert automotive units
Pick a category. Choose length, torque, power, pressure, weight, volume, speed, or temperature from the category menu.
Enter the value you have. Type the number from your dyno sheet, torque wrench, or parts catalog into either side.
Read the paired result and board. Change units on either card, or tap a board tile to set the right-hand unit.
Unit converter FAQ
OEMs and aftermarket brands publish in different systems depending on market. US catalogs often list lb·ft, psi, and inches, while European and Japanese sheets use N·m, bar, and millimeters. A converter lets you cross-check a dyno sheet, torque wrench, or tire pressure chart without guessing.
No. One mechanical horsepower is about 0.746 kW, while one metric horsepower (PS/CV) is about 0.735 kW. On a 400 hp claim the gap is a few horsepower — enough to matter when comparing dyno graphs from different regions.
Yes for unit math (psi ↔ bar ↔ kPa). Still follow the vehicle placard for the recommended cold pressure, and adjust for load or towing with a dedicated tire pressure calculator when you need load-based guidance.
They use standard conversion factors (NIST-style constants for length, mass, and pressure). Display values are rounded for readability — for critical fastener torque or legal speed claims, keep a couple of extra digits from the full readout board.
Engine displacement is a volume. One liter is about 61.02 cubic inches, so a 5.7 L V8 is roughly 348–350 ci depending on the exact bore and stroke. Use the Volume category here for a badge conversion, or the engine displacement calculator when you have bore, stroke, and cylinder count.
Divide millimeters by 25.4 (1 inch = 25.4 mm exactly). ET 35 is 1.38″. Offset is still a length — convert the number, then check poke and backspacing with the wheel offset calculator rather than treating mm as a fitment verdict.
Mechanical horsepower and metric PS use different constants. 400 hp ≈ 298 kW ≈ 406 PS. Pick Power in this converter and leave hp and PS as separate units so a German brochure and a US dyno sheet stay honest.