Make your boat-height input unambiguous.
Convert a recorded measurement, keep the buffer separate, then carry the numbers into the bridge checker. This tool does not measure your boat.
A transparent calculation
Feet + inches ÷ 12 + buffer
Press calculate to see the recorded height, additional buffer and combined requirement in feet and metres.
What is being calculated?
Decimal air draft = whole feet + additional inches ÷ 12. Your entered requirement = decimal air draft + your chosen buffer. Metres = feet × 0.3048. The output is rounded for display; the link to the bridge checker carries the numerical input, not a source observation.
Keep the measurement separate from the decision
A conversion cannot validate the loaded waterline, equipment configuration, bridge geometry or conditions. Confirm the height record and do not use an uncertain figure simply because it produces a convenient margin.
Build a better air-draft record →