A phone clinometer (or inclinometer) uses your smartphone's built-in accelerometer and gyroscope sensors to measure the tilt angle of a surface. When you place your phone flat on your sleeping platform, the device detects gravity's pull relative to its orientation. By reading these tiny shifts, it calculates precise pitch (front-to-back) and roll (side-to-side) angles — effectively turning your phone into a digital bubble level. This tool displays those angles in real time so you can adjust your campsite setup for a perfectly level sleeping surface.

Sleeping on an uneven surface can lead to poor sleep quality, back pain, and discomfort throughout the night. When your platform tilts, you may slowly slide toward one side of your tent or mattress, causing restless sleep. Over time, even a 2-3° tilt becomes very noticeable. For rooftop tents and camper vans, a level platform also ensures proper door alignment, prevents strain on mounting hardware, and keeps gear from rolling around. A quick level check before setting up can make the difference between a great night's sleep and a miserable one.

0–1°: Excellent — you won't notice any tilt. This is the ideal range.
1–2°: Acceptable — most people won't be disturbed, though sensitive sleepers might notice a very slight slope.
2–3°: Borderline — you'll likely feel the incline. Adjust if possible.
3°+: Needs adjustment — the tilt is obvious and will affect sleep quality. Use leveling blocks, rocks, or reposition your vehicle. For reference, a 3° tilt on an 80-inch platform creates about a 4.2-inch height difference from end to end.

Modern smartphones contain high-quality MEMS accelerometers that can detect tilt with accuracy within ±0.1° to ±0.5° under ideal conditions. However, accuracy can be affected by phone case irregularities, sensor drift, temperature, and nearby magnetic fields. For best results, calibrate by placing your phone on a known level surface and using the "Set Current as Level" button. Most devices are more than accurate enough for camping purposes, where 1° precision is perfectly sufficient.

Enter the length of your sleeping platform (the distance from head to foot end) in inches. The tool automatically calculates how many inches you need to raise the low end or low side to achieve level. This uses basic trigonometry: height = platform_length × sin(tilt_angle). For example, an 80-inch platform tilted 2° needs about 2.8 inches of lift on the low end. Use leveling blocks, stacked boards, or purpose-made RV levelers to achieve the recommended height.

This tool uses the W3C DeviceOrientation API, which is supported by all modern mobile browsers including Safari on iOS and Chrome on Android. On iPhones (iOS 13+), you'll need to tap "Enable Sensor" to grant motion permission. Desktop browsers generally do not have accelerometer hardware, so a simulation mode with manual sliders is provided for testing. For the best experience, use a smartphone placed directly on your sleeping platform with the screen facing up.

1. Check first: Park or set up in your initial spot and use this tool to assess the tilt.
2. Identify the low side: The tool tells you which direction is low and by how much.
3. Level side-to-side first: Use leveling blocks or rocks under the low-side wheels/tires. Side-to-side leveling is usually more critical.
4. Then level front-to-back: Adjust your vehicle's position or use additional blocks.
5. Re-check: After adjustments, re-measure to confirm you're within 1°.
Pro tip: Carry a set of interlocking leveling blocks — they're lightweight, stackable, and make fine adjustments easy.

Yes! Use the "Set Current as Level" button to zero out any offset. This is useful if your phone case has an uneven surface, if your phone's sensors have a slight bias, or if you want to measure relative to a specific reference surface. Simply place your phone on a surface you know is level (or the surface you want to treat as your baseline), then click the calibration button. All subsequent readings will be relative to that reference. Click "Reset Calibration" to return to absolute readings.

Pitch (Front-Back Tilt): Measures how much the platform slopes from the head end to the foot end. A positive pitch means the front (top of phone) is higher than the back. This affects whether you'll feel like you're sliding toward the head or foot of your bed.
Roll (Left-Right Tilt): Measures side-to-side slope. A positive roll means the right side is higher than the left. This affects whether you'll roll toward one side of the mattress during the night. Both are equally important for sleep comfort.

Small fluctuations are normal due to sensor noise and micro-vibrations. This tool applies digital smoothing (exponential moving average) to reduce jitter while maintaining responsiveness. If you're seeing large jumps, ensure your phone is resting on a solid surface (not held in your hand), that the surface is free of vibrations (engine off, not on a busy road), and that your phone case isn't rocking. Some older Android devices may experience more sensor noise — in these cases, watch the smoothed reading rather than momentary fluctuations.