Know Your Power.
Test Your Limits.

Yes, WattRamp requires a power meter to calculate your FTP. Heart rate alone is not accurate enough for FTP testing.

WattRamp shows you target power, but doesn't control your trainer (no ERG mode). You manually adjust your effort to match the target. Works great both indoors and outdoors!

Virtual power (estimated from speed/resistance) is not accurate enough for FTP testing. You need a direct power meter — pedal-based, crank-based, hub-based, or a smart trainer with built-in power measurement.

Yes, WattRamp works completely offline. No internet connection, no account, no cloud sync required. All processing happens on your Karoo device. Perfect for remote rides or areas with no signal.

Rest for 1-2 days before testing — avoid hard workouts. Get a good night's sleep, stay hydrated, and eat a normal meal 2-3 hours before. Treat it like a race day: you want to be fresh and ready to give 100%.

WattRamp includes a built-in warmup phase in all test protocols. Just follow the on-screen guidance — no additional warmup needed. If you prefer, you can customize the warmup duration in settings.

Test at the same time you usually train for consistent results. Most cyclists perform best in late morning or afternoon. Avoid testing immediately after waking up or late at night when energy levels are lower.

Eat a light, familiar meal 2-3 hours before. Avoid heavy or new foods. Stay well hydrated in the hours leading up to the test. A small caffeine boost 30-60 minutes before can help if that's part of your normal routine.

Start with the Ramp Test — it's quick, easy to pace, and highly reproducible. Use the 20-minute test for maximum accuracy when you have experience with FTP testing. The 8-minute test is a good middle ground.

The Ramp Test is ideal for beginners, regular progress tracking, and when time is limited. No pacing strategy needed — just follow the increasing power until you can't continue. Great for consistent, comparable results over time.

Use the 20-minute test when you need the most accurate FTP measurement — before a big event, when setting training zones for a serious block, or if you suspect the Ramp Test doesn't suit your physiology (some athletes' FTP differs from the 75% formula).

The 8-minute test uses two max efforts with recovery between them. Choose this if 20 minutes feels mentally too long, or if you respond better to shorter, harder intervals. It's also good if you have strong anaerobic capacity.

The Ramp Test estimates FTP within ±3-5% for most cyclists using the formula: Max 1-minute power × 0.75. Accuracy depends on your physiology — athletes with high anaerobic capacity may get inflated results. WattRamp lets you adjust the coefficient (0.72-0.77) in settings.

Yes, always calibrate (zero offset) your power meter before an FTP test. Let your bike sit for 5 minutes so the power meter reaches ambient temperature, then perform the calibration. This ensures accurate and consistent results.

WattRamp uses minimal battery — similar to any data field. The extension processes power data efficiently. A typical FTP test (20-60 minutes) has negligible impact on your Karoo's battery life.

Yes, completely free forever. No ads, no subscriptions, no premium features, no data collection. WattRamp is open-source — check out the code on GitHub. Built by cyclists, for cyclists.

WattRamp works on Karoo 2 and Karoo 3. Make sure your device runs the latest firmware for best compatibility. The original Karoo 1 is not supported.

Your FTP test is saved as a regular Karoo activity (FIT file). It syncs automatically to Strava, TrainingPeaks, or any platform you've connected. The calculated FTP is stored in WattRamp and shown in your test history.

FTP (Functional Threshold Power) is the maximum power you can sustain for about an hour. It's the foundation of power-based training: your training zones, workout intensities, and race pacing are all calculated from FTP. Regular testing tracks your fitness progress over time.

Power zones are intensity ranges based on your FTP. WattRamp uses the 7-zone model: Zone 1 (Active Recovery), Zone 2 (Endurance), Zone 3 (Tempo), Zone 4 (Threshold), Zone 5 (VO2max), Zone 6 (Anaerobic), Zone 7 (Neuromuscular). Each zone trains different energy systems.

Test every 4-8 weeks during structured training, or after completing a training block. Testing more frequently adds fatigue without useful data. Also retest after a break, illness, or when workouts feel too easy or too hard.

Results can vary due to: fatigue or poor recovery, motivation and mental state, temperature and hydration, uncalibrated power meter, or protocol mismatch with your physiology. Try testing again when fresh, or try a different protocol. You can also adjust the FTP coefficient in settings.

Update your FTP in WattRamp settings and in your training apps. WattRamp automatically calculates 7 power zones from your FTP. Use these zones to structure workouts: Zone 2 for endurance, Zone 4 (threshold) for FTP intervals, Zone 5-6 for VO2max work.

WattRamp automatically handles pauses and resumes when you continue. For the Ramp Test, stopping when exhausted is expected — that's how it works. For 20-min and 8-min tests, try to complete the full effort. If you truly can't finish, the result won't be valid — rest and try again another day.