About BillSmart
A free calculator for splitting group expenses across currencies, plus a small library of guides on handling shared money without friction. Built and run by one person.
Who builds this
My name is Mark. I’m a digital marketing consultant based in Taipei, and I build small web tools in my own time, usually because I hit a problem often enough to get annoyed by it.
BillSmart is built for groups paying in different currencies: one person books the hotel, another covers transport, and everyone needs a clear record of who owes whom. The goal is a page people can use without installing an app or creating an account.
I maintain the site myself and answer the email personally. If something is wrong or missing, telling me is genuinely the fastest way to get it fixed, contact page.
What BillSmart does
- Converts payments made in different currencies into one base currency using published reference rates, and keeps the original and converted amounts together.
- Handles uneven splits, where a given expense only applies to some of the group.
- Reduces the resulting tangle of debts to a short list of transfers that settles everyone.
The how it works page explains the calculation in full, including a worked example and where rounding shows up.
What it deliberately does not do
Every feature that gets left out is a feature that does not need explaining, so the list of omissions is on purpose:
- No accounts. Nothing to sign up for. The calculator keeps entries only while the page is open. Download a PDF before refreshing if you need a record.
- No payments. BillSmart tells you who should pay whom. Moving the money is between you and your bank.
- No receipt scanning, categories, or budgets. Those belong in an app you commit to, not a page you open once on a trip.
How the guides are written
The articles cover the parts of shared spending that a calculator cannot solve: what counts as fair when incomes differ, how to raise money with friends without souring the evening, when cash beats a card abroad.
They are written and edited by me, drawn from ordinary experience rather than professional financial training, and updated when something in them stops being true. The exchange-rate and card-fee guides link to provider and payment-network information. Worked examples are illustrative; the actual fee depends on your bank, card, booking and agreement with your group.
Not financial advice. Nothing here is personalised advice about your money. For decisions with real consequences (taxes, debt, an expense claim your employer will audit), talk to someone licensed in your country.
How the site pays for itself
BillSmart is free and carries advertising. Ads are kept to standard display placements: no pop-ups, no browser push notifications, no interstitials in front of the calculator. If an ad on this site ever interrupts you before you can use the tool, that is a mistake and I want to hear about it.
Advertising has no influence on what the guides say. No article on this site is sponsored, and there are no affiliate links in them.
Elsewhere
Corrections, feature requests and bug reports all go to the same inbox on the contact page. Details on data handling are in the privacy policy, and the usual disclaimers live in the terms of service.