Last updated 28 August 2026
Working backwards from the goal
Most saving advice starts from what's left over at the end of the month, which is why most saving plans quietly fail — whatever is left over is never a fixed amount. Starting from the target instead turns a vague intention into a single number you can either commit to or reject honestly. If the monthly figure looks impossible, that is useful information rather than a failure: it means the deadline needs to move, the target needs to shrink, or something in the budget has to change. Interest helps, but over short horizons it does far less work than the monthly amount itself.
Common questions
How is interest handled?
Interest compounds monthly at the annual rate divided by twelve, and deposits are assumed to arrive at the end of each month. That's the conservative assumption — saving earlier in the month earns a little more than shown.
What if the monthly amount is more than I can manage?
Then the plan needs changing rather than the willpower. Extending the deadline lowers the monthly figure fastest; lowering the target works too. Seeing the real number is the point of working backwards from the goal.
Does the already-saved amount earn interest too?
Yes. Existing savings grow at the same rate for the full period, which is why a head start reduces the monthly figure by more than the head start itself.
Is my information stored anywhere?
No. The calculation runs in your browser and nothing is uploaded or saved.