Jeremy

Most online financial calculators work the same way. You put in a number and see what comes out the other end. That works fine — until you already know what you want the answer to be.

If you're walking into a salary negotiation, you don't want to guess and check. If you're working out whether you can afford a house, you want to start from the property — not from some arbitrary income figure. If you're trying to save for something specific, you want to know what you need to put away each week, not how much you'll end up with.

That's the whole idea here. Start with the end in mind. Tell the calculator what you're trying to achieve — and let it work backwards to give you the number you actually need.

I built these tools because I kept running into this problem myself. I hope they're useful for you too.