there is also the question of how accurate the tape is (class 1, class 2, or
worse than that), see
In search of accurate measurements for a
vernier adapter I designed to work with metric tape measures (and a discussion
on tape measure accuracy). Rockler has a good imerial/metric tape measure that’s
a class 2 tape that’s not that expensive ($10)
https://www.rockler.com/fastcap-procarpenter-standard-metric-tape-measure