Calculators for the bay.
The arithmetic that comes up on a working day - converting what one gauge reads into what another does, reading a sidewall, allowing for a hot tyre, and finding out whether an air line is choking the tool on the end of it. Free to use, nothing to sign up for.
PSI, bar, kPa and kg/cm2 side by side. Indian workshop gauges are printed in all four and a placard rarely uses the one in your hand.
Decode a sidewall marking into overall diameter, sidewall height, rolling circumference, load capacity and speed rating - then compare a replacement size and see the speedometer error it introduces.
A tyre checked warm reads high, and letting the air out to correct it leaves it flat when it cools. Work out either direction properly, in absolute pressure, instead of by rule of thumb.
How much pressure a run of hose costs you at a given flow, and what the same run would do in every common bore. An impact wrench that will not shift a nut is often the hose, not the gun.
BSP, NPT or metric? Measure the thread and count it, and see every standard thread that matches. The pair that catches everyone out is 1/4 BSP against 1/4 NPT.
Will the compressor run the tool, how long does it take to pump up, and how long does the tank last once the tool outruns it? A receiver holds far less usable air than its size suggests.
From flat to working pressure, with the air volume worked out from the sidewall marking. Tells you whether a small inflator is worth the wait.
N-m, kgf-m, lb-ft and lb-in, plus the correction for an offset adapter - and a straight answer on when a socket extension changes the torque, which is less often than people think.
Standard physics, published tables, and nothing else.
Every figure these tools produce comes from a gas law, a flow equation or the published ISO load and speed tables. None of them assert an Air Flow specification, a pressure figure for your vehicle or an air consumption figure for a particular tool. Where a calculation had to assume something - air temperature, hose wall roughness, the atmospheric pressure a gauge reads against - the page says so next to the result.
For the pressure a vehicle actually needs, use the placard on the door pillar or the handbook. For a product specification, use the item on its catalogue page.