Bill Splitter

About Bill Splitter

How Bill Splitting Works

A simple equal split divides the total (including tip) by the number of people. The formula is:

Per person = (Bill + (Bill x Tip%)) / Number of people

For example, a meal costing £86.40 with a 15% tip split four ways works out as: £86.40 + £12.96 tip = £99.36 total, so £24.84 per person. The tip calculator can help if you want to work out the tip amount separately before splitting.

Uneven splits are common when one person orders a starter and a main while another just has a salad. Toggle uneven mode to assign custom amounts and the tool tracks the remaining balance so you know when everything adds up.

There are two main approaches to uneven splitting, and choosing the right one depends on how different the orders were:

• Itemised split - each person pays for exactly what they ordered. This is the fairest method when there are large differences in spending, such as one person ordering a bottle of wine while others stuck to tap water. The downside is that someone has to go through the receipt line by line, which slows things down.
• Proportional split - one person estimates rough totals per head (for example, "you two had mains and desserts, so maybe £35 each, and the rest of us had just mains at £20 each"). This is faster than itemising but still accounts for big differences. It works well for groups of four to six where the broad strokes are obvious.

For groups where everyone ordered roughly the same thing, equal splitting is fine and avoids the hassle entirely. The general rule: if the most expensive order is less than twice the cheapest, an equal split is usually fair enough that nobody minds.

Group Expense Settlement - the Maths Behind It

When a group shares multiple expenses over time, working out who owes whom gets complicated quickly. With five people and ten expenses, there could be up to 20 individual debts. The settlement algorithm simplifies this to the fewest transactions possible.

The process works in three steps:

1. Calculate net balances - for each person, add up everything they paid and subtract everything they owe. A positive balance means they are owed money. A negative balance means they owe money.
2. Sort by balance - rank everyone from largest creditor to largest debtor.
3. Pair and settle - match the person who is owed the most with the person who owes the most. The smaller of the two amounts is transferred, zeroing out one side. Repeat until all balances are zero.

Here is a worked example. Four friends go on a weekend trip. Alice pays £200 for the accommodation, Bob pays £60 for groceries, Carol pays £80 for dinner, and Dave pays nothing. The total is £340, so each person's fair share is £85.

Person	Paid	Fair Share	Net Balance
Alice	£200	£85	+£115 (owed)
Bob	£60	£85	-£25 (owes)
Carol	£80	£85	-£5 (owes)
Dave	£0	£85	-£85 (owes)

Without the algorithm, you might end up with six separate transfers between different people. The greedy settlement pairs Dave (-£85) with Alice (+£115) first. Dave pays Alice £85, zeroing Dave out and leaving Alice at +£30. Next, Bob (-£25) pays Alice £25, leaving Alice at +£5. Finally, Carol pays Alice £5. Three transactions instead of six, and everyone is square.

This greedy algorithm produces optimal or near-optimal results for most real-world groups. A group of five people with a dozen shared expenses typically settles in just three or four transactions rather than the dozen or more that individual reimbursements would require. For mathematicians: the minimum number of transactions to settle a group of N people is at most N-1, and the greedy approach hits this bound in almost every practical case.

How Much Does a Restaurant Meal Actually Cost?

According to the Office for National Statistics Family Spending bulletin, UK households spend around 7% of total weekly expenditure on restaurants and hotels, with around £1,419 a year on takeaways, restaurants, cafés and snacks combined. A typical restaurant meal for two in the UK costs between £40 and £70 depending on location and type of venue, with London averaging 20-30% higher than the national figure. In the US, the average dine-in ticket sits around $54 per person as of 2025, though this varies widely by state, city, and venue type.

Meal Type	Average Cost (UK, 2 people)	Average Cost (US, 2 people)	Typical Tip
Casual dining	£35 - £55	$40 - $70	0 - 10% (UK) / 15 - 18% (US)
Mid-range restaurant	£55 - £90	$80 - $130	10 - 12.5% (UK) / 18 - 20% (US)
Fine dining	£120+	$150+	12.5 - 15% (UK) / 20%+ (US)
Pub meal / diner	£25 - £40	$25 - $45	Optional (UK) / 15% (US)

Tipping customs vary significantly by country, and getting it wrong can be either rude or wasteful depending on where you are. Here is a reference for the most common destinations:

Country	Tipping Norm	Notes
United States	15 - 20%	Expected at sit-down restaurants. Servers rely on tips as a significant part of their income. Below 15% is considered poor.
United Kingdom	10 - 12.5%	Appreciated but not obligatory. Many restaurants add a discretionary service charge. You can ask for it to be removed.
France	Not expected	Service is included in prices by law (service compris). Rounding up or leaving a euro or two for good service is a nice gesture.
Germany	5 - 10%	Rounding up to the nearest euro is standard. Say the amount you want to pay when handing over cash.
Italy	Not expected	A coperto (cover charge) of 1-3 euros per person is common. Additional tipping is uncommon except at high-end venues.
Japan	Do not tip	Tipping can be considered rude. Good service is a matter of professional pride and is reflected in the bill.
Australia	Not expected	No obligation, but 10% is increasingly common at upscale restaurants. Staff are paid a living wage.
Canada	15 - 20%	Similar to the US. 15% is the baseline, 18-20% for good service.

The percentage calculator is handy for working out exact tip amounts on unusual percentages. When splitting a bill internationally, decide upfront whether to include the tip in the split or have each person add their own.

Common Bill Splitting Mistakes

Even with a calculator, certain mistakes come up repeatedly when groups split bills:

• Forgetting tax - in the US, sales tax is added after the listed menu prices. A $100 bill might actually be $108-$110 depending on state and city tax rates. If you split based on menu prices and forget the tax, someone ends up covering the difference. Always split on the final total, not the subtotal.
• Not accounting for drinks - this is the single biggest source of bill-splitting frustration. Alcohol can easily double a person's share. If half the table orders cocktails and wine while the other half drinks water, an equal split penalises the non-drinkers. A practical middle ground: split food equally and have each person pay for their own drinks.
• Tipping on the pre-discount total - if the restaurant applied a voucher, loyalty discount, or promotional deal, the tip should generally be based on the original (pre-discount) total. The server did the same amount of work regardless of the discount. This catches people out especially with group deals.
• Shared items falling through the cracks - starters for the table, a bottle of wine split between three people, or a shared dessert can get lost in an itemised split. The simplest approach is to divide shared items equally among everyone who had some, then add that to each person's individual total. A £45 bottle of wine split three ways adds £15 to each person's share, which is easy to forget when you are only looking at your own mains and sides.
• Rounding errors compounding - when you round each person's share down, the shortfall accumulates. Four people each rounding down by 20p leaves 80p uncovered. Six people rounding down on a larger bill can leave £3-4 short, which the person paying usually has to cover out of pocket. Always round up rather than down, and let the person who collects the money keep any small overage. Most payment apps like Monzo and Revolut handle this by splitting to the penny, avoiding the problem entirely.
• Forgetting who already paid - on group trips where expenses pile up, it is easy to lose track of who covered what. The Group Expenses mode in this tool tracks every payment in real time, which avoids the end-of-trip argument about who bought lunch on Tuesday.

For managing a monthly household budget rather than one-off expenses, the budget calculator uses the 50/30/20 rule to help you allocate income across needs, wants, and savings. And if you need to work out how much VAT was included in a restaurant bill (common for business expense claims), the VAT calculator can extract the VAT portion from a gross amount.

Sources

• ONS - Family Spending in the UK
• GOV.UK - Family Food FYE 2024
• National Restaurant Association - Research and Data
• Investopedia - Tipping Customs by Country
• NerdWallet - How to Split a Bill Fairly