Crawl Ratio Calculator
Calculate your vehicle's crawl ratio for optimal off-road performance
Calculate Crawl Ratio
First gear ratio (typical: 2.5-4.0)
Low range ratio (typical: 2.0-4.0)
Differential ratio (typical: 3.0-5.0)
Crawl Ratio Results
Formula: Crawl Ratio = TG × TCR × AGR
Calculation: 0 × 0 × 0.00 = 0.00
Performance Analysis
Example Calculation
Ford C4 Off-Road Setup
Transmission (1st gear): 2.46:1
Transfer Case (low range): 2.72:1
Axle Differential: 3.73:1
Calculation Steps
Crawl Ratio = TG × TCR × AGR
Crawl Ratio = 2.46 × 2.72 × 3.73
Crawl Ratio = 24.95:1
Category: Factory/Daily Driving
Performance Categories
Factory/Daily
Standard settings for road use
Light Trail
Road and light off-road
Intermediate
Moderate obstacles
Extreme
Rock crawling capability
Off-Road Tips
Higher crawl ratio = better obstacle control
Lower crawl ratio = better for daily driving
Tire size doesn't affect crawl ratio
Smaller tires provide more ground force
Understanding Crawl Ratio
What is Crawl Ratio?
Crawl ratio determines how many engine revolutions are needed to rotate the tire one complete revolution. It's calculated by multiplying the transmission gear ratio, transfer case ratio, and axle differential ratio together.
Why is it Important?
- •Predicts vehicle performance in different conditions
- •Determines optimal setup for intended use
- •Helps with gear selection for modifications
- •Affects torque multiplication and control
Crawl Ratio Formula
Crawl Ratio = TG × TCR × AGR
- TG: Transmission gear ratio (1st gear)
- TCR: Transfer case ratio (low range)
- AGR: Axle gear ratio (differential)
Note: Higher ratios provide more torque multiplication and better control at low speeds, ideal for technical off-road driving.
Component Explanations
Transmission Ratio
The gear ratio in first gear, typically ranging from 2.5:1 to 4.0:1. This is the largest gear connected to the smallest gear in the transmission.
Transfer Case Ratio
The low-range ratio in 4WD vehicles, typically 2.0:1 to 4.0:1. This reduces speed and increases torque for off-road situations.
Axle Ratio
The differential ratio calculated from ring gear teeth divided by pinion teeth, typically 3.0:1 to 5.0:1.