Lump sum interest calculator

Simple projection for one deposit.

Built and reviewed by Dovanic, Founder and editor, FreeByteLast reviewed: 2026-08-18

Deposit

Rate

Years

Final balance

$19,838

Interest

$4,838

Show in today's money

With these inputs, final balance comes to $19,838 over 7 years. Interest works out to $4,838. The result assumes rate stays at 4%.

Over time · by years

Input	−10%	Now	+10%
Deposit	$17,854	$19,838	$21,821
Rate	$19,292	$19,838	$20,399
Years	$19,061	$19,838	$20,646

Whatmakesequal

Save this set of inputs, change something, then save again to compare the outcomes side by side.

Simple projection for one deposit.

With the defaults above, final balance works out at $19,838.