Piggy Bank Savings Goal Calculator

Work out piggy bank savings goal instantly with clear inputs, formula shown and shareable results.

About Piggy Bank Savings Goal Calculator

Time to a savings goal is what is left divided by the rate of saving, with monthly extras converted to a weekly equivalent. Showing progress as a percentage matters more than it sounds: visible progress is the single strongest predictor of sticking with a savings plan.

Formula

Savings goal

weeks = (goal - saved) / (weekly + monthly extra / 4.348)

Worked example

With the default values below, Piggy Bank Savings Goal Calculator returns Weeks to reach the goal of 12.03. Change any input above and every figure here is recalculated in your browser.

Inputs used

Savings goal: 240
Saved so far: 68
Amount saved each week: 12
Extra added each month: 10

Results

Weeks to reach the goal: 12.03 weeks
Still to save: $172.00
Months to reach the goal: 2.77 months
Progress: 28.3% %

Step by step

1Values used
2Savings goal
3Weeks to reach the goal= 12.03 weeks
4Still to save= 172.00
5Months to reach the goal= 2.77 months
6Progress= 28.3 %

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Should a child's savings earn interest?

At these amounts interest is negligible, but a small matched contribution from a parent teaches the same lesson far more effectively.

What if the goal keeps moving?

Fix the target and the date. A moving goal removes the sense of progress that makes saving work.