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 came out of a group trip. Four of us, three currencies, one person fronting the hotel, someone else covering the car, and a running note on a phone that nobody trusted by day three. The existing apps all wanted everyone to install something and create an account, which is a hard sell at a restaurant table at eleven at night. I wanted a page you could open, use, and close.
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 shows the rate used for each entry.
- Handles uneven splits, where a given expense only applies to some of the group.
- Reduces the resulting tangle of debts to the shortest 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, and nothing stored between visits.
- 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. Where an article touches on fees or exchange rates, it points at the primary source so you can check the number yourself rather than take my word for it.
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.