Power to Finish / Bike Power Plan calculator (race split projection)

What it does

The Bike Power Plan calculator — shown in the app as Power to Finish — takes your physical inputs (CP, weight, CdA) and a course profile, and projects the bike split for a target race. It is the bridge between training thresholds (CP, W') and race-day pacing (target watts, projected time).

URL: /calculators/ then open the Power to Finish entry (the route viewer with the course map). From the wizard, it is step 4 (Bike Power Plan). Its advanced mode ("Power Strategy") paces the loaded course segment by segment, with separate powers for short / medium / long climbs, a descending cap, and wind — see the loaded-route map below the inputs.

Inputs the calculator pulls

The Bike Power Plan depends on outputs of earlier calculators when run inside the wizard:

CP and W' from the Critical Power calculator.
CdA from the CdA calculator.
Body mass from the athlete profile.
Course profile (distance, elevation gain, climbs).
Conditions (altitude, temperature, wind if available).

Run standalone, you enter these values manually.

Prefill and units

Opened from an athlete page or race (the URL carries athlete_pid / race_id), the calculator pre-fills from the athlete's current data: FTP/CP and CdA from their latest tracked metrics (the same source the dashboards read), rider weight from the profile, and bike weight from their primary bike. Race goals (target power, race-specific CdA) overlay on top of those defaults. A banner confirms what was filled; stale metrics are flagged.

The Unit choice selector follows your saved unit preference automatically — imperial users get lb / mph input fields without touching the toggle, and can flip it at any time. Speed results always show both systems, e.g. 32.00 km/h (19.88 mi/h).

Outputs

Projected bike time (the saved key output: finishTimePhysics).
Average target watts (avg_w).

When run from the wizard, both outputs surface on step 4's card on the wizard dashboard. They feed into the Finish Time calculator at step 5.

How to read the output

The projected time assumes you hold the target average power across the full bike leg. Variability in your actual ride (climbs, headwinds) can push real time longer than projected even with the right average. The calculator does the math; the discipline is yours.

In strategy mode the Normalized Power (NP) shown uses the standard 30-second rolling 4th-power average over the modelled power, so on rolling terrain (frequent climb/descent power changes) it reflects the real physiological cost rather than a plain average. On a steady course NP and average power are close.

When to rerun

After any change to CP (post-test).
After any change to CdA (new position, new equipment).
If race conditions change materially (altitude, expected temperature).