> ## Documentation Index
> Fetch the complete documentation index at: https://docs.budgetbandit.io/llms.txt
> Use this file to discover all available pages before exploring further.

# How money is stored

> The app stores amounts as whole numbers for exact precision. You always see and enter dollars.

Budget Bandit stores every amount as a whole number internally, not as a decimal.
This is a precision choice, and it is the reason the math always adds up to the cent.
You never have to think about it — you see and type dollars everywhere.

## Why whole numbers

Computers are bad at decimals. Store $0.10 as a decimal and add it ten times and you
can drift to $0.9999999 instead of \$1.00. Across a budget with thousands of
transactions, those rounding errors pile up and balances stop matching.

The fix is to store money as an integer count of a tiny unit, then divide for
display. Budget Bandit keeps four digits of precision under the hood, so \$1.00 is
stored as a round whole number and every sum stays exact. Reconciling an account to
the cent works because there is no hidden fraction to chase.

## You always work in dollars

This is purely an internal detail. Everywhere you look or type, the app is in
dollars:

* You enter `45.99` and the app records \$45.99.
* You read \$1,240.00 Available, not a count of internal units.
* Reports, totals, and exports are all in dollars and cents.

You will never be asked to enter or read an internal unit. If a number ever looks off
by a rounding error, that is a bug worth reporting — the storage model exists
precisely to prevent it.

## Next

<CardGroup cols={2}>
  <Card title="Reconcile an account" icon="scale-balanced" href="/reconciling/reconcile-an-account">
    Match the app to your statement, down to the cent.
  </Card>

  <Card title="Sync and privacy" icon="shield" href="/concepts/sync-and-privacy">
    How the same exact numbers stay in sync across your devices.
  </Card>
</CardGroup>