Split shared costs fairly with housemates or a partner

Help me split shared costs fairly.

Shared costs: [rent, bills, food, with amounts]
People: [names, incomes if they're happy to share, rooms/sizes if relevant]
What feels unfair now: [details]
What we want: [simple method we can stick to]

Ask me up to 3 short questions first if anything important is missing. Wait for my answers.

Then:
1. Two or three fair methods (equal, income-based, room-based) with a worked example on our numbers.
2. Pros and cons of each.
3. A Google Sheets layout to track who paid what.
4. A short house agreement paragraph.

Only use what I've told you, leave blanks for anything I haven't given, and don't invent facts, figures or products. UK English.

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