How to use it
Start with her size in metres, and say whether she lives on a home mooring or cruises without one. From that the licence line fills itself in. Already paying a licence? Put your own figure in its box and that is used instead.
Then add your own figures for the rest, a year at a time: mooring, insurance, engine servicing, diesel, heating, pump-outs and anything else. Some costs come round every few years, like the Boat Safety Scheme examination and blacking the hull. For those, type the cost and how many years it covers, and the calculator spreads it.
How it is worked out
Each line is turned into a cost a year. A cost every few years is divided by the years it covers. The lines are added up. The total is divided by 12 for a month and by 52 for a week.
Why most boxes start empty
We fill in the licence line for you, because the Canal & River Trust's prices give it for her exact size. The other lines start empty. Moorings, insurance and upkeep vary hugely with the boat, the place and who you use. We'd rather leave the box empty than print a typical figure we can't stand behind. Ask for quotes, and type in the real numbers.
More to read
For what each cost is and how it is charged, read the cost of living on a narrowboat and what it costs to run a narrowboat. The licence on its own is in the licence calculator.
Sources
The licence line uses the prices we read from the Trust's online calculator on 30 October 2026; a note beside the answer says when they were last confirmed. Every other figure is yours.