I haven't used a lap day calculator very often, but from what I've seen, the results depend on the values you enter for speed, distance, and total time. Even a small change to one of those numbers can noticeably affect the final calculation, so it's worth double-checking your inputs if something looks off. I like using calculators that clearly show how the result is worked out. The same goes for a maternity pay calculator seeing a clear breakdown makes it much easier to understand the figures and plan ahead with confidence.