Litres consumed per 100 kilometres; lower is better. Standard metric efficiency unit.

Energy lost deforming tires as they roll. Low-pressure or wide tires raise it.

Automotive Calculators

Steering Ratio Calculator

2026-09-27 6 min

Steering ratio and road-wheel travel per wheel revolution from lock-to-lock turns and inner-wheel angle.

Steering Ratio: 14.4 :1
Road Wheel Per Rev: 25.0 deg/rev; Center-to-lock travel per wheel turn

Calculator

Lock to Lock(turns)

turns

Inner Wheel Lock(deg)

deg

Results update live as you type

Live statistics

Steering Ratio

14.4 :1

Road Wheel Per Rev

25.0 deg/rev

Center-to-lock travel per wheel turn

Results

Optimal

Steering Ratio

14.4:1

Road Wheel Per Rev

25.0deg/rev

Center-to-lock travel per wheel turn

Planning estimate from standard automotive formulas. Validate with dyno, timeslip or datalog data when precision matters.

Visualizations

Results overview

14.4Steering Ratio

25Road Wheel Per Rev

Steering Ratio vs. Lock to Lock

Steering Ratio

14.4:1

525

Formula

Steering-wheel degrees (center to lock) divided by road-wheel degrees at lock.

Ratio = (lock-to-lock x 360 / 2) / road angle

Alternative Form

Road per rev = road travel / lock-to-lock turns

Variables

Symbol	Name	Unit	Description
N	Lock-to-lock turns	turns	Full steering-wheel travel
delta	Road-wheel lock	deg	Inner-wheel angle at full lock

Explanation

Quick ratios (12-14:1) feel darty; slow ratios (16-20:1) feel calm — same lock, different hand motion.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Record the inputs.

Lock to Lock:2.8 turns

Inner Wheel Lock:35 deg

Result: 2 inputs ready

Step 2

Apply the formula.

Ratio = (lock-to-lock x 360 / 2) / road angle

Result: Primary result = 14.4 :1

Step 3

Read every derived output.

Steering Ratio:14.4 :1

Road Wheel Per Rev:25.0 deg/rev

Result: Steering Ratio = 14.4 :1

Final Answer

14.4

Worked Examples

See how the calculator works with different scenarios.

Scenario

Sport-sedan rack.

Inputs

Lock-to-lock:2.8 turns

Lock:35 deg

Calculation

504/35 = 14.4:1; 25 deg/rev

Result

14.4:1 ratio.

Interpretation

Quick sporty rack; parking takes less arm work than a 17:1 cruiser.

Understanding Your Result

Your Result: Steering Ratio: 14.4 :1

What This Means

How many steering-wheel degrees move the road wheels one degree.

Why It Matters

Sets steering quickness, effort and parking friendliness.

Professional Interpretation

Treat the primary result as a planning estimate, then validate on a dyno, at the track, or with logged sensor data. If measured numbers disagree by more than ~10%, re-check inputs (units are the usual culprit) before changing parts.

Recommendations

•Double-check units on every input before trusting the result
•Compare against the worked example below to sanity-check magnitude
•Validate with measured data (dyno, timeslip, datalog) when it matters

Learn — fuel economy, deeply

Steering ratio translates hand motion into tire direction.

1 · Where the gallon goes (energy path)

Engine heat

60–70% lost

Coolant + exhaust carry most energy away. Hybrids recover some via Atkinson cycle + regen.

Driveline

5–15% lost

Transmission, differential, accessories. CVTs and 8–10 speed autos lose less.

Aero drag

∝ v²

Doubles from 55→78 mph. Roof boxes hurt more than trunks.

Rolling + brakes

10–20%

Tires, weight, stops. Regen braking (hybrid/EV) reclaims city braking energy.

4 · Measure like a pro (the 3-tank protocol)

Fill to first click at the same pump, record the odometer (Tank 0).
Drive normally for 2–3 tanks; always refill to first click at the same pump.
MPG = total miles ÷ total gallons across all tanks — averaging kills pump-click noise.
Cross-check with the trip computer; a persistent >10% gap means the computer needs calibration — or the car needs service.
Log with an OBD-II dongle for per-trip MPG if you want to isolate commute vs. highway behavior.

Practical Tips

•Variable racks quote an average — note it
•Faster ratios need more assist tuning
•Compare road-per-rev for parking feel

Common Mistakes

Mixing units (inches with mm, psi with kPa)

Convert every input to the unit shown on its field before calculating.

Trusting a single output blindly

Cross-check with the worked example and, when it matters, a dyno or datalog.

Assumptions

This calculator makes the following assumptions to provide estimates:

Steady-state model: Formulas assume stabilized conditions; transients, heat soak and traction limits are excluded.

Standard factors: Empirical constants (BSFC, VE, drivetrain loss) use typical values — your combination may differ.

Limitations

Be aware of these limitations when using this calculator:

Estimate, not measurement: Predictions carry real-world scatter of roughly ±5–15% depending on the model.

No transient effects: Shift time, wheelspin, spool lag and heat soak are not modeled here.

Frequently Asked Questions

Answers to common questions about this calculator.

What is a quick steering ratio?

Under ~14:1 feels quick; 15-17:1 is typical; trucks and cruisers run 18-22:1.

Does ratio change with speed?

Variable-ratio racks do — they run quicker near center for stability plus fast lock for parking.

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Related Guides

Deepen your understanding with these educational resources.

Automotive Guides

Build planning, measurement protocol and validation how-tos

Glossary

Technical terms used in mortgage calculations explained in plain language.

MPG: Miles per gallon. Distance travelled per gallon of fuel; higher is better. US gallon = 3.785 L.
L/100 km: Litres consumed per 100 kilometres; lower is better. Standard metric efficiency unit.
MPGe: Miles per gallon-equivalent. EV metric: miles travelled on 33.7 kWh (energy of 1 gal of gasoline).
CAFE: Corporate Average Fuel Economy — US fleet-average efficiency standard enforced by NHTSA.
Rolling resistance: Energy lost deforming tires as they roll. Low-pressure or wide tires raise it.
Aerodynamic drag: Air resistance growing with the square of speed — why highway MPG falls fast above 60 mph.
Hypermiling: Driving techniques (coasting, steady speed, anticipation) that maximise real-world MPG.
OBD-II: On-board diagnostics port. Scanners and dongles read live MPG, fuel trim and fault codes.

Authoritative References

Trusted sources and standards referenced by this calculator.

EPA — FuelEconomy.gov DOE — Fuel-Efficient Driving Tips NHTSA — Driving Safety & Efficiency SAE International — Fuel Economy Standards Consumer Reports — MPG Truth IRS — Standard Mileage Rates

Applicable Standards

EPA Fuel Economy Testing (40 CFR Part 600)CAFE — Corporate Average Fuel Economy Standards (NHTSA)WLTP — Worldwide Harmonised Light Vehicle Test ProcedureSAE J1321 / J1711 — Fuel consumption test proceduresISO 2575 — Road vehicles symbols & efficiency markings

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Page Information

Last Updated:

2026-09-27

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.