Cycling to Running Conversion: What's the Real Ratio?

The real cycling to running conversion ratio ranges from 1:2.5 to 1:4, depending on your intensity levels. At moderate effort, 1 km of running equals approximately 3 km of cycling in terms of metabolic load. This ratio is based on MET (Metabolic Equivalent of Task) values from the Compendium of Physical Activities.

Understanding the relationship between cycling and running is essential for cross-training, triathlon preparation, and substituting workouts when needed. Let's dive into the science behind these conversion ratios.

Use our Cycling to Running Conversion Calculator to get your personalized ratio based on your actual speeds and intensities.

The Common "1:3 Rule" Explained

You've probably heard that "1 mile of running equals 3 miles of cycling." This rule of thumb exists because at typical recreational intensities:

Running at 8 km/h (5 mph) = approximately 8.3 METs
Cycling at 20 km/h (12.5 mph) = approximately 8.0 METs

At similar MET values, if you exercise for the same duration, you'll cover about 3 times the distance on a bike compared to running. This creates the 1:3 ratio.

MET Values: The Foundation of Conversion

MET (Metabolic Equivalent of Task) represents the energy cost of an activity relative to sitting quietly at rest (1 MET = 3.5 ml O₂/kg/min).

Cycling MET Values by Speed

Cycling Speed	MET Value	Intensity Level
16-19 km/h (10-12 mph)	6.8	Light effort
19-22 km/h (12-14 mph)	8.0	Moderate
22.5-26 km/h (14-16 mph)	10.0	Vigorous
26-30 km/h (16-19 mph)	12.0	Racing
30+ km/h (19+ mph)	12.0-16.0	Very fast

Running MET Values by Speed

Running Speed	Pace	MET Value
8.0 km/h (5 mph)	7:30/km	8.3
9.7 km/h (6 mph)	6:10/km	9.8
11.3 km/h (7 mph)	5:18/km	11.0
12.9 km/h (8 mph)	4:39/km	11.8
14.5 km/h (9 mph)	4:08/km	12.8

Notice that running generally has higher MET values per unit speed compared to cycling. This is why running burns more calories per minute at comparable perceived efforts.

Why the Ratio Changes with Intensity

The conversion ratio isn't fixed—it shifts based on your effort levels:

Your Effort	Typical Ratio	Why
Easy spinning vs. easy jog	1:4	Low cycling MET, moderate running MET
Moderate for both	1:3	METs are roughly balanced
Hard cycling vs. moderate run	1:2.5	High cycling MET approaches running
Racing intensity for both	1:2 to 1:2.5	METs converge at high intensities

The MET-Minutes Formula

To calculate equivalent workouts, we equalize MET-minutes:

MET-minutes = MET value × duration in minutes

For example:

60 km cycling at 25 km/h = 2.4 hours = 144 minutes at ~10 METs = 1,440 MET-minutes
To match with running at 10 km/h (~9.8 METs): 1,440 ÷ 9.8 = 147 minutes
Running distance: (10 km/h ÷ 60) × 147 = 24.5 km

This gives a ratio of 60:24.5 or approximately 1:2.45 for these specific intensities.

Practical Conversion Charts

Quick Reference: Cycling to Running Distance

Cycling Distance	Easy Effort (1:4)	Moderate (1:3)	Hard (1:2.5)
10 km	2.5 km run	3.3 km run	4 km run
20 km	5 km run	6.7 km run	8 km run
30 km	7.5 km run	10 km run	12 km run
40 km	10 km run	13.3 km run	16 km run
60 km	15 km run	20 km run	24 km run
100 km	25 km run	33.3 km run	40 km run

Imperial Version: Miles

Cycling Distance	Easy Effort (1:4)	Moderate (1:3)	Hard (1:2.5)
10 miles	2.5 mi run	3.3 mi run	4 mi run
20 miles	5 mi run	6.7 mi run	8 mi run
30 miles	7.5 mi run	10 mi run	12 mi run
50 miles	12.5 mi run	16.7 mi run	20 mi run

Energy Cost Approach: The 1 kcal/kg/km Rule

For more precision, you can use the established sports science rule that running costs approximately 1 kcal per kg of body weight per km, regardless of pace (within normal running speeds).

This means:

Calculate total cycling calories using: Calories = MET × weight (kg) × time (hours)
Find equivalent running distance: Distance = Calories ÷ weight

For a 70 kg person cycling 40 km at 25 km/h (1.6 hours at 10 METs):

Cycling calories: 10 × 70 × 1.6 = 1,120 kcal
Equivalent running: 1,120 ÷ 70 = 16 km

This gives a 40:16 ratio or 1:2.5—consistent with the hard effort ratio.

ACSM Equations for Power-Based Conversion

If you train with a power meter, the ACSM leg ergometry equation provides the most accurate conversion:

VO₂ = 7 + 10.8 × (Power in watts ÷ Body mass in kg)

Example for a 70 kg cyclist averaging 180W for 90 minutes:

VO₂ = 7 + 10.8 × (180 ÷ 70) = 34.8 ml/kg/min
Calories/min = (34.8 × 70 / 1000) × 5 = 12.2 kcal/min
Total calories: 12.2 × 90 = 1,098 kcal
Equivalent running distance: 1,098 ÷ 70 = 15.7 km

When to Use Each Conversion Method

Use Quick Ratios When:

You need a rough estimate
You don't know exact speeds
You're planning weekly training volume

Use MET-Based Conversion When:

You know your cycling and running speeds
You want a personalized ratio
You're planning specific workout substitutions

Use Power-Based Conversion When:

You train with a power meter
You need maximum accuracy
You're doing structured training

Important Caveats

While metabolic equivalence is useful for comparing training load, remember:

Running has higher impact stress - Bones and joints experience 2-3x body weight forces with each stride
Muscle activation differs - The eccentric loading in running creates more muscle damage
Sport specificity matters - For race performance, nothing replaces sport-specific training
Individual variation exists - Running economy and cycling efficiency vary between people

Use these conversions for general training load comparison, not as exact race preparation substitutes.

Calculate Your Personal Ratio

Ready to find your exact cycling-to-running conversion? Use our Cycling to Running Conversion Calculator to input your specific speeds and get a personalized ratio.

For more on cross-training and workout equivalence:

How to Convert Cycling Miles to Running Miles - Practical step-by-step guide
Cycling vs Running Training Equivalence - When to substitute one for the other
Cycling vs Running for Weight Loss - Calorie comparison for fat loss