Many digital meters have a 10A range. Being digital, they can display up to 19.99, but the test leads might not live through that.
Apart from meters that have external "range resistors", which are neither common nor cheap, an old world solution was to use an ammeter from a car scrapyard, which could be had in 30 and 60 amp versions. And things like the watts up meter. Some might record the figures for posterity.
Then there are clip-on or clamp meters that you clip over the wire without interrupting it and take a reading from the magnetic field generated by the current.
The down and dirty method is to get a bag of assorted fuses and experiment, noting the two values where failure happens regularly, and the higher value where it doesn't.