I've always found spreadsheets useful, but for one-off calculations they can sometimes be more work than they're worth, especially when you have to build the formulas yourself. We've been working on this problem with some NHS-related calculations. Annual leave is a good example because entitlement changes with length of service, contracted hours and bank holidays, and part-time staff often need everything calculated pro-rata. We ended up making a simple NHS annual leave calculator for it: http://nhspaycalculatorss.co.uk/nhs-annual-leave-calculator/ You enter the relevant details and it handles the calculation rather than having to set up a spreadsheet. I'm curious what others here prefer for this sort of thing. Do you still make a quick spreadsheet when you need to calculate something, or are dedicated web calculators becoming the easier option?