How to Add and Split an Expense in FairSplitter
Step-by-step guide to adding expenses and splitting bills equally, by exact amount, by percentage, or by shares in FairSplitter.

FairSplitter lets you split any expense equally, by exact amount, by percentage, or by shares — all from a single screen. Here's exactly how to do it.
How to Add an Expense
- Open FairSplitter. You land on the Home tab, which shows your net balance and a list of friends.
- Tap the + button in the bottom-right corner of the screen.
- The "Add an expense" screen opens. Fill in the fields:
| Field | What to enter |
|---|---|
| Description | What the expense is for — e.g., "Dinner at Mario's" |
| Amount | The total cost — e.g., 84.00 |
| Date | Defaults to today; tap to change |
| Category | Tap to choose a category |
| Currency | Defaults to your preferred currency |
| Split with | Search for friends by name or select from contacts |
| Group | Optional — attach the expense to a group |
| Paid by | Defaults to "You" — tap to change if someone else paid |
- Tap Save in the top-right corner. Balances update immediately.
Shortcut: On any friend's detail screen, tap the + button to add an expense with that friend pre-filled in the "Split with" field.
How to Choose a Split Method
By default, FairSplitter splits the expense equally. To change how it's divided:
- On the "Add an expense" screen, tap the split row — the line that shows how the expense will be split.
- The Split Options modal opens with four tabs.
Equal
Divides the total evenly among everyone included.
When to use: Restaurant bills where everyone ordered similarly, shared accommodation, any cost that should be split the same way.
Example: $90 dinner, 3 people → each person owes $30.
Exact
You type the precise dollar amount each person owes. Amounts must add up to the total.
When to use: One person ordered significantly more, someone didn't have a drink, any situation where the amounts aren't the same.
Example: $90 dinner — Alice had more courses:
- Alice: $45
- Bob: $25
- Carol: $20
- Total: $90 ✓
Percent
You assign a percentage to each person. Percentages must total 100%.
When to use: Splitting rent by room size, recurring bills where one person uses more, any split based on a ratio rather than a fixed amount.
Example: $1,200 rent — larger room vs. smaller room:
- Alice (larger room): 60% → $720
- Bob (smaller room): 40% → $480
Shares
You assign a number of shares to each person. FairSplitter calculates each person's proportion from the total shares.
When to use: Groups where some people consume more (e.g., families with children counted as half-shares), or when you want to express ratios without doing percentage math.
Example: $120 grocery run — one person bought more:
- Alice: 2 shares
- Bob: 1 share
- Total: 3 shares → Alice owes $80, Bob owes $40
Changing "Paid by"
If someone other than you paid, tap Paid by on the expense form and select the correct person. This is important — FairSplitter uses the "Paid by" field to calculate who is owed money back.
Example: Bob pays $90 for dinner with Alice and Carol, split equally:
- Set Paid by to Bob
- Alice and Carol each owe Bob $30
- Bob's balance goes up by $60
Editing or Deleting an Expense
To edit: Open the expense from the Activity tab or from a friend's detail screen → tap Edit → change any field → tap Save.
To delete: Open the expense → tap Delete. All affected balances recalculate immediately. The deletion is recorded in the activity history so everyone can see what changed and when.
Common Questions
Can I split an expense between only some members of a group?
Yes. When adding the expense, set the Group field to your group but only add the specific people in the Split with field who were actually part of this expense. The others won't be affected.
What if I save with the wrong split method?
Open the expense, tap Edit, then tap the split row to change the method. The balances update automatically when you save.
Can I change who paid after saving?
Yes — open the expense, tap Edit, change the Paid by field, and save. Balances recalculate immediately.
Does the currency matter per expense?
Yes. Each expense can use a different currency. FairSplitter handles the conversion so balances are shown in a consistent currency for each person or group.