How this instrument works
Cadence is how fast the pedals are turning, measured in revolutions per minute (rpm). A cadence sensor on a modern bike computer counts every revolution automatically, but the underlying idea is simple enough to measure by hand: count pedal strokes with one leg over a timed interval, then scale that count up to a full minute.
This instrument does exactly that scaling. Enter how many revolutions you counted and how many seconds you counted them over, and it multiplies the rate by 60 to give revolutions per minute — the same field method cycling coaches have used for decades before cadence sensors were affordable or common.
Cadence matters because two riders can travel at identical speed while spinning completely different rpm, depending on the gear each has chosen. A higher cadence shifts load toward the cardiovascular system and away from the leg muscles, which is why most coaches recommend a spin somewhere around 85-95 rpm for general road riding, with lower cadences favoured for climbing strength work and higher cadences used in short sprint efforts.
- Count pedal revolutions with a stopwatch running — count every time one specific leg reaches the bottom of the pedal stroke for consistency.
- Enter that count into Pedal revolutions counted.
- Enter the number of seconds you counted over into Time (seconds); 15-20 seconds is usually enough for a stable reading.
- Read Cadence (rpm) — this is your pedalling rate scaled up to a full minute, ready to compare against a target training cadence.
- Time must be greater than zero, and the revolution count can't be negative — the instrument will prompt you if either is left blank or invalid.
Worked example — 30 pedal strokes in 20 seconds
Enter 30 into Pedal revolutions counted and 20 into Time (seconds) — a rider counts 30 full pedal strokes with one leg over a 20-second stretch of steady riding. Cadence reads 90.00 rpm.
That figure sits right in the middle of the 85-95 rpm range most cycling coaches recommend for efficient road riding, so a rider seeing this number knows their current gear choice is a reasonable match for that pace without needing to shift up or down.
Questions
What counts as a good cycling cadence?
Most coaches recommend roughly 85-95 rpm for general road riding, since it balances load between the legs and the cardiovascular system better than either extreme. Racing cyclists often push toward 90-100 rpm or higher, climbers sometimes drop into the 60-80 rpm range to favour muscular strength, and short sprint efforts can spike well past 120 rpm.
Why measure cadence by counting instead of using a sensor?
Not every bike has a cadence sensor fitted, and counting is a useful way to spot-check a sensor's reading or to get a number on any bike, including a borrowed or rental one. Counting pedal strokes with one leg over 15-20 seconds and scaling to a minute, exactly what this instrument does, has been standard coaching practice since long before affordable electronic sensors existed.
Does a higher cadence make me faster?
Not on its own — speed depends on cadence combined with gear ratio and wheel size, not cadence alone. This site's bike-cadence-and-speed-calculator instrument takes a gear ratio and wheel circumference alongside cadence to work out actual road speed; this page only measures the pedalling rate itself, independent of whatever gear is engaged.
Why do low and high cadence feel so different for the same effort?
A low cadence in a tall gear asks the leg muscles for more force per pedal stroke, which fatigues muscle fibres faster even at a similar power output. A high cadence in a shorter gear spreads that same power across more, lighter pedal strokes per minute, shifting the strain toward the heart and lungs instead — which is why spinning a higher cadence often feels 'easier' on the legs even while breathing harder.
How long should I count revolutions for an accurate reading?
15 to 20 seconds is a practical minimum — long enough to smooth out the natural unevenness between individual pedal strokes, short enough to count reliably without losing track. Counting for a full 60 seconds removes the need to scale the number at all, but 15-20 seconds with the ×60 scaling this instrument applies is the standard field-check length coaches use.
Can I use this while riding, or only stopped?
It works either way, since it's just doing the arithmetic after you've counted — the counting itself is easiest done while holding a steady effort on a flat or a stationary trainer, where cadence stays consistent for the full interval. Counting during a climb or a variable-effort stretch will give a less representative reading.