Bubble level
Lay the phone flat to get a round “bullseye” level that shows the tilt left-right and front-back, the total tilt, and the slope in percent and millimetres per metre. Stand it on its edge and it becomes a tube level showing how far it is from horizontal or vertical. Hold freezes the reading, and the phone vibrates when it is level.
How to calibrate
Phone sensors are rarely mounted perfectly straight, and a camera bump tilts a phone lying on its back. Calibration removes both:
- Put the phone on a flat, stable surface and press Calibrate.
- Hold still for a second while ToolBench takes the first reading.
- Turn the phone 180° on exactly the same spot and let it take the second reading.
The two readings cancel out the slope of the surface itself and leave only the sensor’s error, which is then subtracted. After calibration a typical phone is accurate to a few tenths of a degree.
Compass
The compass shows the heading and the cardinal direction of the top edge when the phone lies flat, or of the back camera when you hold it upright. Press Mark this bearing to see how far left or right you are drifting from it. If you have chosen a place in the Sun and moon tab, the sun and moon are drawn on the dial too, which helps to check the direction outdoors.
A phone compass points to magnetic north. To get true north, enter your local magnetic declination; ToolBench links to the NOAA calculator for it. Keep the phone away from magnets, speakers, laptops and steel, and if the reading looks wrong, move the phone in a figure-of-eight a few times to recalibrate the magnetometer.
Protractor
- On screen: drag the two arms with a finger, the mouse or the arrow keys (Shift for 0.1° steps) to measure an angle in a picture or an object placed on the screen. You get the angle, its supplement, the full-circle value and radians.
- Phone tilt: stand the phone on its edge to measure rotation from 0 to 360°, or lay it on a surface to measure its slope. Set zero here makes the current position zero, so you can measure the angle between two surfaces, for example a door and its frame.
Sound level meter
Press Start and allow the microphone. ToolBench turns off noise suppression, echo cancellation and automatic gain, so the level is not “helped” by the phone, and shows:
- dB(A), weighted like human hearing and used for noise rules; dB(C) for loud and bass-heavy sound; dB(Z) without weighting.
- Fast (125 ms) or slow (1 s) response, the average level over time (Leq), minimum, maximum, peak and a one-minute chart.
- A scale with everyday examples, from a quiet room to a concert.
Phone microphones are not certified instruments: they vary from model to model and limit very loud sound. Treat the result as an estimate within a few decibels, and if you have a reference meter, use the ±1 dB calibration to match it.
Sun and moon
Choose a place: your current location, a place saved in WhereBench, or coordinates you type in. ToolBench calculates for any date:
- Sunrise and sunset with their direction, day length and how it changed since yesterday, solar noon, and the sun’s height and shadow length right now.
- Golden hour (sun between −4° and +6°), when light is warm and soft, and blue hour (between −6° and −4°), in the morning and in the evening.
- Civil and astronomical twilight, and polar day and night.
- Moon: phase, illumination, age, moonrise and moonset, and the next full and new moon.
Sun times are accurate to about a minute, moon times to a few minutes. Times are shown in your device’s time zone; if the place is in another zone, you can switch to it. Share a link to a place and date, or copy the times as text.
Privacy and requirements
Everything is calculated on your device; ToolBench makes no outside requests. Sensors and the microphone work only over HTTPS, and on iPhone motion access is requested with a button. When the tab is hidden, sensors and the microphone switch off; while you measure, the screen is kept on. The measurement log is kept only on your device and only when you press Save to log; it can be exported as CSV for Excel. On a computer without motion sensors, ToolBench opens on Sun and moon.
Frequently asked questions
How accurate is a phone level?
After calibration, a few tenths of a degree, which is a few millimetres per metre. That is good for hanging shelves and pictures; for building work, check with a real level.
Why does the compass point the wrong way?
Nearby metal and magnets disturb the magnetometer. Move away from them, wave the phone in a figure-of-eight, and remember that the compass shows magnetic north unless you enter the declination.
Can a phone measure decibels accurately?
Within a few decibels for normal sound levels. For legal or workplace measurements you need a certified sound level meter.
When is golden hour today?
Open the Sun and moon tab with your location: the morning and evening golden hour are shown on the day scale with exact times.
Does ToolBench work on iPhone?
Yes. Safari asks for permission to use motion and orientation the first time you open the level, compass or protractor.