Writing
On sharing money.
Long answers to the questions people actually ask about splitting costs with the people they live with, travel with, or are married to. Worked numbers, not platitudes.
31 articles
Start here7 min read
How to split shared costs fairly
Five ways to divide a shared cost, and how to pick. On one household and one total, the method changes what somebody pays by $548.58. Start here.
Read the overviewLiving together
79 min read
Should your roommate’s partner be paying toward the bills?
Almost nobody objects to a guest. They object to a fourth person’s share of the bills landing on three people. At half the week that is $70.00 a month.
8 min read
How to split the cost of a shared pet
Nobody has ever fallen out over $65 of kibble. The two things that go wrong are the emergency bill nobody saved for and the day one of you moves out.
8 min read
Splitting rent and bills in a student house
Five people, one house, and about an hour of decisions in week one. Get them right and the whole year is five standing orders, from $677.57 down to $568.43.
8 min read
How to split the cost of a shared car
Gas money covers under a quarter of what a mile costs. Once depreciation, insurance and servicing are in, the owner is donating about 39 cents of every mile somebody else drives.
8 min read
When your partner moves into an apartment you already share
The bedroom is already paid for. What changes is that the shared space now holds three people, which means the couple owe a second share and the roommate should be paying less.
8 min read
How to split utility bills when usage isn’t equal
One of you works from home with the heating on, one is out all day, one is away ten nights a month. An even split charges all three the same for very different amounts of electricity.
9 min read
How to split rent when the bedrooms aren’t equal
One of you has the big room with the ensuite. The arithmetic that fixes it, the mistake almost every rent-split guide makes, and the part no formula can settle.
Couples and income
57 min read
How to split bills when your income changes every month
One salary, one income that moves. Compare a monthly percentage with a three-month average, and agree what happens when a low month arrives.
9 min read
How to split bills when only one of you is earning
Fifty-fifty is arithmetically impossible, and splitting by income sends the whole $2,940 to one person. What fair looks like when one income is zero.
9 min read
How to split bills when one of you has debt
Two people earning the same amount do not have the same money. An $800 loan payment moves a $2,760 month from an even split to $1,285.61 and $1,474.39.
8 min read
When you earn much more and want to pay for everything
A generous offer and usually the wrong one, for a reason that has nothing to do with money: paying zero makes somebody a guest in their own home.
8 min read
How to split bills when one of you earns more
An even split sounds fair and usually is not. The arithmetic, the three methods worth considering, and a straight recommendation.
Trips and travel
67 min read
How to split bachelorette trip costs without surprise bills
Covering the bride is a gift that needs a price. A six-person weekend, optional activities, a live calculator and a budget message you can copy.
7 min read
How to split an Airbnb between couples and singles
Two couples, two singles and a friend on the sofa. Compare three ways to divide a $2,520 booking, with a calculator that keeps every cent.
9 min read
How to split the cost of a road trip
Fuel was $55.74 of a $224.62 trip. Split only the gas and the person who drove quietly absorbs $168.88 in tires, servicing and wear nobody sees.
8 min read
When someone drops out of a trip you have already booked
One number decides most of this: how much of the money is already gone. On an $1,800 house booked for six, the entire argument is worth $60 a head.
9 min read
Splitting expenses in different currencies after a trip abroad
The question is not which exchange rate to use. It is when you fix it, because a trip converted at the end quietly changes what everybody owes every day nobody settles up.
8 min read
Splitting a trip when people come for different parts
A house is a per-night cost, not a per-person one. Split three ways, the guest who stayed two nights of five pays double the nightly rate everyone else does.
Settling up
79 min read
How do you split money after a breakup?
The arithmetic is rarely the hard part. A record made while nobody was angry settles in ten minutes what memory argues about for weeks.
8 min read
How much should everyone chip in for a group gift?
Wrong question, and asking it is what leaves the organizer out of pocket. On a $420 present for nine, a normal set of replies leaves $89.98 unpaid.
8 min read
Closing the books when you move out
Four things settle when somebody leaves, and two of them are always skipped. Done properly the person leaving is owed $179.00 on the day, not handing over $62.00.
8 min read
When one person pays for everything on a group trip
Somebody fronts the flights and the deposit and everyone settles at the end. That quietly makes them the group’s lender: $2,412.50 out of pocket against a fair share of $1,017.50.
7 min read
Splitting $10 three ways: where the extra cent goes
Rounding each share does not just lose a cent. Sometimes it collects more than the bill. The rule that always adds up, and why the tie-break is not arbitrary.
8 min read
When someone doesn’t pay you back
Five small things over two months quietly became $159.05. The exact figure, the message that actually gets it sent, and what to do when it still does not arrive.
9 min read
The fewest payments that settle everyone up
Six shared expenses across five people is 21 paybacks done item by item, or four done properly. The method, the limit on how few is possible, and where the usual algorithm loses.
Bills and receipts
39 min read
How to split the cost of shared subscriptions
A four-plan bundle is $671.52 a year on one person’s card. Split an upgrade evenly and $56.04 a year moves toward the people who never asked for it.
8 min read
How to split groceries when people eat differently
One vegetarian, one who buys the good coffee, one who drinks the beer. An even split charges the person eating least $11.91 more than their food costs, every week.
8 min read
How to split a bill by what each person ordered
Assigning the items is easy. Tax and tip are where almost every calculator goes wrong, and on this bill it costs the person who ordered a salad $9.25.
Choosing a tool
28 min read
A joint account, an app, or a spreadsheet?
Most households need two of the three. Includes a free working spreadsheet with the formulas already written, and no email address to hand over for it.
9 min read
Splitwise alternatives, honestly compared
Four apps that split shared costs, what each one puts behind a paywall, and where each is genuinely the better pick. We make one of them, so the places we lose are marked.
Prefer to just do the maths?
Six free calculators that run in your browser, no account and no email. They use the same split engine as the app, so the answers match to the cent.
See the free tools