Every figure on this site is exact where a standard fixes it, and honest about tolerance where a real object varies. Here is exactly how we decide.
Each object on RulerCue carries one of three labels, so you always know where the number came from.
A tolerance is the honest range an object actually falls in. We set it three ways. Where a spec gives a manufacturing tolerance, we use it. Where an object varies by brand, like a paperclip or a sugar cube, we measure several and show the spread. Where a single standard fixes the size, we mark it exact and give no range.
We never write about eight inches and leave it there. If it is exact we say so; if it varies we say by how much.
If a figure is set by the maker or a standards body, re-measuring adds nothing and risks introducing our own error. A US quarter is 0.955 inches to the Mint specification, full stop. In those cases we cite the authority and move on. We only measure in house when no reliable published figure exists, or when we want a photograph with a ruler in frame to prove it.
Many everyday objects are not standardised. A sandwich loaf, a coffee mug, a golf tee: these vary by maker. When that happens we say so plainly, give the common range, and pick a typical mid-point as the headline figure. The goal is a number you can rely on, not a false precision.
Read the labels on each object this way. Exact means a standard or spec fixes it to the millimetre. Close means it is a dependable reference within a small, stated tolerance. Estimate means it varies enough that you should treat it as a ballpark, such as a thumb width.
If we did not verify a figure against a ruler, a spec, or a standard, it does not go on the page. That is the whole rule.
