One link. They open it, add their income, and the split updates for everybody — no account needed.
The link works for 90 days and holds only the names and amounts entered here.
よくある質問
Two methods are defensible and this calculator does both. An even split divides every shared cost by the number of people — simple, and the norm between roommates who each keep their own finances. A proportional split divides by share of combined income: someone earning $6,000 against a partner earning $3,000 covers 66.7% of the bill instead of 50%. Proportional splitting leaves both people with a similar percentage of their income left over, which is why couples with a large income gap tend to prefer it.
Not automatically — it depends on what "fair" means to the household. Even splitting treats the expense as shared equally regardless of who earns what, and works well when both incomes are close or when both people want strict financial independence. It bites when the gap is large: on $2,620 of shared costs, an even split leaves the person earning $3,000 with $1,690 and the person earning $6,000 with $4,690. The proportional view in this calculator shows both numbers side by side so the household can decide with the figures in front of them rather than in the abstract.
Press "Create shareable link" and paste the link into your group chat. Anyone who opens it sees the same numbers and can add their own income or a missed expense — no account, no app install, nothing to sign up for on either side. The link stays live for 90 days and the clock resets every time somebody edits it.
Anything everybody uses: rent or mortgage, utilities, internet, groceries you cook together, household supplies, a shared streaming subscription, transport you split. Costs only one person benefits from — an individual phone plan, personal subscriptions, a gym membership — normally stay out of the split. The usual friction point is groceries: if one person eats most of the food, splitting them evenly is where resentment starts, so either track them separately or weight them.
Use take-home (net) pay. Gross income overstates what a higher earner actually has available once tax, pension contributions and health deductions come out, and the two people may be taxed at very different effective rates. Net pay is also the number both people can verify from a payslip, which matters when the split is a negotiation.
Split rent by room value rather than by head. A common approach is to divide rent by square footage or by what each room would rent for individually, then split every other bill evenly. Enter the resulting rent figures as separate expense lines rather than trying to make one percentage cover both rent and utilities.
It expires 90 days after the last edit and stops resolving. Nothing on the page is tied to an account: it holds the names people typed for themselves, the amounts, and a currency. If you want a permanent record of who paid what over time, that belongs in an expense tracker rather than a link.