Guides
The awkward situations, and how to get out of them.
Questions of method and of tact, answered in a few minutes of reading. Each guide covers one specific situation rather than a general theme, and points to the tool that does the maths where there is one.
Method
How to work it out when the split is not obvious.
Bedrooms of different sizes: should everyone pay the same rent?
What justifies a rent gap between rooms, what does not, and how to work it out without charging the difference twice.
A flatmate leaves mid-lease: how to recalculate
Pro-rating the part-month, the deposit, outstanding bills, and what the joint liability clause really changes.
Ski weekend: splitting costs when not everyone skis
What the whole group shares, what only concerns the skiers, and the case of someone skiing a single day.
A friend arrives two days later: how to adjust their share
Pro-rating by nights, what does not get pro-rated, and the case of a day visitor.
Fuel and tolls: how to split a shared car journey
Does the driver pay a share, should vehicle wear count, and how to split between two unevenly filled cars.
Splitting the bill when some people did not drink
Why alcohol breaks an equal split more than anything else, and two ways to handle it without counting every cent.
Does a couple count as one share or two?
The deciding criterion is not the couple but the consumption, and why two lines beat one double share.
Situation
What the maths does not settle: asking, following up, raising it without breaking the group.
How to ask a friend to pay you back without looking petty
The right moment, the right wording, and why the amount matters less than the time elapsed.
The friend who always pays less: how to bring it up
Telling forgetfulness apart from a deliberate imbalance, and the conversation that settles it without breaking the group.
Someone disputes a group expense: how to settle it
Go back to the line rather than the balance, what can still be renegotiated, and the rule to set for next time.
Why a shared expenses spreadsheet dies after three weeks
It is neither the formulas nor discipline: the cost of entry falls on one person while the benefit goes to the group.