Why can't you add the balances directly?

Hong Kong dollars, US dollars and Japanese yen are different units. To calculate total assets, first convert account balances to a single currency rather than adding the numbers shown on each account.

Use the same approach for debts. Converting foreign-currency assets while leaving out foreign-currency loans or credit card balances will overstate your net worth.

Choose a base currency

Your base currency is the currency you use to view totals. If your income, spending and main debts are in Hong Kong dollars, HKD may make comparisons easier. If you mainly use another currency, choose the one that fits your records.

Once chosen, try to keep it consistent. Changing the base currency changes the units shown on your charts; it does not mean your assets have increased or decreased.

Keep original balances and convert the totals

Keep each account's balance in its original currency, then convert it for the overview. This lets you check against bank statements while still seeing your overall asset allocation.

Converted amount = Original balance × Base currency per unit of the original currency

Check which way the exchange rate is quoted. For example, Hong Kong dollars per US dollar is the inverse of US dollars per Hong Kong dollar. Using the rate in the wrong direction gives an incorrect result.

  • Record the original balance and currency code for each account.
  • Check the base currency and quotation direction before converting.
  • Use rates from the same date, or dates close together.
  • Convert both foreign-currency assets and foreign-currency debts.

Why can the total change when the original balance stays the same?

Even if an account's original balance is unchanged, its value in your base currency can move as exchange rates change. An increase in net worth should not automatically be treated as new savings or an investment gain.

When comparing two dates, first check whether the original balance changed, then check the exchange rates used. This helps distinguish account changes from conversion effects. It is not a complete investment-return attribution calculation.

Avoid double counting transfers

When you transfer money from an HKD account to a USD account, update both accounts. Recording the incoming funds before deducting them from the source account can temporarily overstate the total. The reverse can understate it.

For investment accounts, check whether the account's total already includes cash and holdings. You can record the whole account or its individual assets, but do not count both at the same time.

How does WorthBook handle currencies?

WorthBook supports HKD, USD, CNY, JPY, EUR, GBP, SGD, AUD, CAD and TWD. Each account can keep its own currency, with totals converted to your base currency using rates you set.

You enter and update exchange rates yourself; they are not live market quotes. The app does not connect to banks or update investment prices automatically. Check statements regularly, update balances and rates, then review the overview.

If you have not yet organised your assets and debts, start with What is net worth? How to calculate your assets and debts to establish a consistent approach.