Endurometry
What does this calculator do?
The printable wristband builds a 40 mm × (wrist + 2.5 cm overlap) strip with cumulative time and segment pace at each 1 / 2 / 5 / 10 km or mile mark. Strategies: even, or a ±5% linear ramp (negative / positive).
Print at 100%, wrap once, tape the overlap. No cutting into tiles. Pro printing is a billing gate; the on-screen band is the same geometry.
How does it work?
Average pace = goal time ÷ distance in the chosen unit. For even, every segment uses that pace. For negative, segment i of n gets factor = 1 − 0.05×(2i/n − 1): early segments slower, late faster. Positive inverts the sign. Cumulative time is the running sum of (segment pace × segment length). The last row uses the true leftover distance (42.195 km, not 45).
Font size shrinks to fit n rows in the strip. The ±5% ramp is an Endurometry layout choice, not a published race-physiology model.
Formula
avg = goal / distance_in_unit ramp_i = 2i/n − 1 // −1 … +1 factor_even = 1 factor_neg = 1 − 0.05 × ramp_i // slow then fast factor_pos = 1 + 0.05 × ramp_i seg_pace = avg × factor cumulative += seg_pace × seg_length paper = wrist(S15/M17/L19 cm) + 2.5 cm overlap
Times to a second. Goal 1 min–8 h.
Worked example
Default: marathon 4:00:00, km, even, every 5, wrist M (17 cm).
- Even pace = 14,400 / 42.195 → 5:41/km
- Rows at 5, 10, … 40 km plus 42.195 km finish
- Paper length = 17 + 2.5 = 19.5 cm, width 40 mm
- Negative would start ~5% slower than 5:41 and finish ~5% faster, still summing to 4:00:00
Generate: a wrap-around band whose last cumulative is 4:00:00 at 42.195 km.
How to interpret the result
Read one line per marker: left clock, right that segment’s pace. Even means every kilometre is 5:41. Negative is an Endurometry ±5% ramp, not “what elites do at Boston.”
Card grid without wrap: pace band generator. Goal plus VDOT zones: pace chart.
Assumptions and limitations
Assumptions
- You hold the chosen strategy’s paces, not GPS-adjusted distance.
- Wrist S/M/L are 15 / 17 / 19 cm as labelled.
- Print scale is 100%.
Limitations
- The ±5% ramp is ours, not a study protocol. Elites often use smaller gaps.
- No hills, wind or aid walking in the numbers.
- Very many 1 km rows can force tiny type; pick 5 km if unreadable.
- Times outside 1 min–8 h rejected.
Methodology and sources
Method type: Exact calculation
Even splits are an exact definition. Negative and positive apply a linear ±5% pace ramp of Endurometry’s so that the sum still equals the goal. Distances are World Athletics road standards. Geometry is 40 mm by wrist+2.5 cm.
Sources: NIST SP 811 · World Athletics Book of Rules
Last reviewed: October 5, 2026