CalcIsland

CalcIsland is a free set of finance calculators for tax, retirement, investing, mortgages, and currency. Enter your numbers and get results instantly, with no sign-up. Every calculator shows its formula and assumptions, so you can see where the numbers come from. Region tools cover Hong Kong, the US, the UK, and Japan.

Key features

• ✓Formula and assumptions shown on every calculator
• ✓Free to use, no sign-up
• ✓Tax, retirement, mortgage, and currency tools