Drag Factor Calculator

By the Watta Team · Updated March 2026

The drag factor calculator estimates the aerodynamic resistance experienced by the flywheel on a Concept2 ergometer at different damper settings. Drag factor (measured in units displayed on the PM5) is not the same as damper setting — the damper controls airflow into the fan cage, while drag factor is the actual measured resistance that the flywheel encounters. The same damper setting produces different drag factors depending on machine age, fan cage cleanliness, altitude, and temperature. Most competitive rowers use a drag factor between 120-140 on the RowErg, which corresponds to approximately damper 4-6 on a well-maintained machine. Higher drag factors simulate heavy boats or headwind; lower drag factors simulate light boats or tailwind.

Drag Factor Estimator

5
spm
Estimated Drag Factor142Moderate — balanced between rate and powerRecommended range for RowErg: 120–140

How This Works

Select your machine type (RowErg, SkiErg, or BikeErg) and damper setting. The calculator provides an estimated drag factor range based on typical readings for that machine type at that damper position. Note that this is an approximation — for precise measurement, check "More Options > Display Drag Factor" on your PM5 during a workout. The calculator also shows the recommended drag factor range for your machine and describes how the selected drag factor will feel during rowing.

Formula

Drag Factor ≈ base_drag + (damper_setting - 1) / 9 × (max_drag - base_drag)

Examples

RowErg at damper setting 4

Estimated drag factor of approximately 120 — the sweet spot for most recreational and competitive rowers.

RowErg at damper setting 7

Estimated drag factor of approximately 173 — significantly heavier than recommended, may reduce stroke rate and increase lower back load.

SkiErg at damper setting 5

Estimated drag factor of approximately 122 — within the recommended range for general SkiErg training.

Benchmarks

LevelValue
RowErg — Recommended120-140 (damper 3-5)
RowErg — Lightweight105-125 (damper 2-4)
SkiErg — Recommended100-130 (damper 3-6)
BikeErg — Recommended40-70 (damper 3-6)
Competition StandardSelf-selected (check PM5)

Watta Integration

Watta captures your erg display data including any drag factor shown on screen. Track how your performance varies at different drag factor settings over time.

Frequently Asked Questions

Related Content

Split to Watts ConverterEffort Score CalculatorTraining Pace CalculatorDrag FactorDrag factor is a numerical value (typically 80-220) that represents the resistance or air resistance experienced during each stroke on a rowing ergometer.Damper SettingThe damper setting is the adjustable lever (1-10) on the side of a Concept2 rowing ergometer that controls airflow to the flywheel and affects resistance.Concept2 RowErgThe Concept2 RowErg (formerly Model D/E) is the industry-standard air-resistance rowing ergometer used by Olympic teams, universities, CrossFit boxes, and home gyms worldwide.Erg Technique GuideRowing for Beginners
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