Free apps and calculators

Each app comes with a calculator that works right here, with no sign-up and no data sent to any server.

• Stairo

  Work out the steps, tread and riser of a staircase.

• Terrao

  Measure the area and perimeter of a land plot.

• Rakkora

  Classify damage to pallet racking.

• VanVolto

  Choose the cable, fuse and battery for your van. Coming soon.