Concept2 ergometers display pace, watts, and calories per hour on the performance monitor (PM) during a workout. Below is an interactive chart that displays each of these, as well as speed, to help in planning and performing your workouts. Mouse over or tap to see metrics at a given pace.

Below are descriptions of the terms and math involved in calculating the verious metrics in the above graph. Reading these is not necessary.

Note: formulas are presented in MathML, currently unsupported in the Google Chrome browser.


Pace is the length of time in seconds to cover a set distance. In the chart above, it is shown on the X axis, starting at 3:00 and going down to 1:00.

The PM shows split, which is pace over 500m for RowErg and SkiErg, and 1000m for BikeErg. It is the basis for other metrics in the chart above.

split seconds = split distance metres × work time seconds work distance metres


The PM shows power (P) each stroke, measured in watts.

P watts = 2.8 split seconds 500 metres 3

Calories per hour

The PM shows calories per hour. This is roughly how many calories a 79.5kg individual would “burn” over an hour based on the last recorded stroke variables of power (P) and time (t).

First we calculate the mechanical work (W) in kilojoules:

W kJ = P watts × t seconds 1000

Then we determine calories per hour (E) based on this mechanical work W and time t of the stroke:

E calories per hour = 4 × W kJ + 0.35 × t seconds 4.2

(See The Physics of Ergometers section 11 for information on the constants)


Speed is not displayed by the PM. It is calculated by scaling the pace across an entire hour, and is measured in kilometres per hour (kph).

Speed kph = split distance metres Pace seconds × 60 minutes × 60 seconds 1000 metres

Note: speed is calculated and shown here to provide rough equivalency between Concept2 ergometers and other machines in terms of distance and time. This does not equate effort nor energy expenditure.


The above formulas and notes are summarised from original works by Concept2 and Anu Dudhia. More detailed information can be found by following the links below.

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