50/30/20 Budget Calculator
A budget framework simple enough to remember, which is the only kind anybody keeps using after the first month.
What the rule says
The 50/30/20 rule, popularised by Elizabeth Warren and Amelia Warren Tyagi, splits take-home pay three ways:
Needs are housing, utilities, groceries, transport to work, insurance, and the minimum payment on any debt. The test is whether skipping it causes a real problem: missing rent does, cancelling a streaming service does not.
Wants are everything discretionary, including the more expensive version of a need. Food is a need; a restaurant meal is a want. The distinction is not moral — wants are not a failing — it is about which numbers you can move when you need to.
Savings counts anything that improves your net position: pension contributions, emergency fund, investments, and overpayments on debt.
When the rule does not fit
The 50 % needs figure is unrealistic in many expensive cities, where housing alone can consume 40 % of take-home pay. That does not make the framework useless; it makes the target aspirational rather than descriptive.
More useful adaptations:
- On a lower income, needs will exceed 50 % and there is nothing to be done about it. The relevant goal is getting savings above zero, not hitting 20 %.
- On a higher income, needs should fall well below 50 % and the savings share should rise. Letting spending expand to fill the allowance is the mechanism by which high earners end up with nothing.
- With expensive housing, try 60/20/20 and protect the savings line first.
- With high-interest debt, treat the 20 % as debt repayment until it is cleared. Saving at 4 % while paying 22 % makes no sense.
The principle worth keeping is not the exact percentages. It is that savings should be a fixed allocation made first, not whatever happens to survive the month.
Making it work
- Start from bank statements, not memory. Take three months of actual transactions and categorise them. Almost everyone underestimates discretionary spending, usually by a lot.
- Pay yourself first. Set a standing order for the savings amount on payday. Saving what is left at month end reliably produces nothing left.
- Watch the unallocated line. If income minus tracked spending leaves a gap, that gap is untracked spending. Finding it is usually the single most valuable thing this exercise does.
- Budget annual costs monthly. Insurance, car tax, birthdays and holidays are not surprises. Divide the annual total by twelve and set it aside.
- Review quarterly, not weekly. Enough time to see a pattern; not so much that problems compound.
Order of operations, if you are starting from nothing: build one month of essential expenses as a buffer, clear any debt above roughly 8 % interest, then build the full emergency fund, then invest. Our emergency fund calculator sizes the buffer.
Frequently asked questions
Is 20% savings realistic?
For many people, not immediately. It is a target rather than a starting point. Saving 5 % consistently beats aiming for 20 % and abandoning it in month two — and the rate tends to rise naturally as income grows, provided you resist expanding spending to match.
Do pension contributions count as savings?
Yes. Employer pension contributions count too, and they are the highest-return part of most people's finances — an employer match is an immediate guaranteed return that no investment can beat.
What if my needs are over 50%?
Common, particularly with high housing costs. Focus on protecting the savings line rather than hitting the exact percentages, and treat reducing housing costs as the one change with enough leverage to matter — it is usually the largest single line item.
Should I budget gross or net income?
Net — your take-home pay after tax and deductions. That is the money you actually allocate. Budgeting gross income produces a plan for money you never receive.