Skip to main content
Focused proof page

Long-term planning

Compound Interest Calculator as proof.

A focused ShowMath proof page for compound growth. Show how visible math turns a planning calculator into something trustworthy and teachable.

Best sent when

Send this when someone needs a planning proof point that feels calmer and more universal than tax or pricing math.

Share route

/showmath/examples/compound-interest

Situation

A saver wants to see how a starting balance plus monthly contributions compounds over time.

Why this earns trust

People hear that compounding is powerful, but the trust comes from seeing how time, rate, and contribution cadence interact.

What becomes visible

  • How the exponent changes the curve over time
  • Why earlier contributions matter more than later ones
  • What actually happens when you change the rate, years, or monthly deposit

Formula sketch

Future value = Principal ร— (1 + rate รท compounding periods)^(periods ร— years)
Contribution growth = Each deposit compounds for a different number of periods
Total ending balance = Principal growth + contribution growth

Other proof routes

Send the proof point that fits the moment.