Spendwise
What the 50/30/20 rule actually says
The rule became popular through Elizabeth Warren and Amelia Warren Tyagi's All Your Worth (2005). The claim is narrow and useful: of the money that arrives in your account, half can go to obligations, three tenths to discretionary life, and one fifth to the future. Nothing in the split depends on your salary, your country, or your bank.
The strength is that it is a ceiling on needs, not a target for them. Most budgeting advice tells you to spend less and save more without saying what less means. Here, the 50% line is a diagnosis: if necessities cross it, the problem is structural — rent, transport, childcare — and no coupon app fixes it.
How to read the three numbers
- Needs, 50%. Rent or mortgage, utilities, groceries, transport to work, insurance, minimum debt payments, essential medication. The test is simple: would you still pay this in the first month of unemployment?
- Wants, 30%. Restaurants, subscriptions, travel, hobbies, a nicer phone than you need. This is the bucket that pays for the shortfall when the other two are tight — and the first place to look when savings slip.
- Savings and debt, 20%. Emergency fund, retirement, investing, and anything above the minimum on a loan. Paying down expensive debt is the highest-return savings available, so it belongs here rather than in needs.
On 4,000 a month that is 2,000, 1,200 and 800. The daily figure — roughly 133 — is not part of the original rule. It is there because a monthly number is too large to feel during a week, and the question "can I afford this today" is the one people actually ask.
Where the categories blur
Every 50/30/20 argument is really an argument about one expense. Some calls that survive scrutiny:
- Groceries are a need; the delivery fee is a want. Split them. A takeaway habit filed under food can hide a four-figure annual wants budget.
- The car is mixed. The loan, insurance and fuel for the commute are needs; the upgrade trim is not. If you could commute by bus in a pinch, the honest needs figure is the bus fare, and the difference is a want.
- A gym is a want — unless a doctor prescribed it. Memberships you would cancel in a bad month are wants by definition, however healthy.
- Minimum debt payments are needs; overpayments are savings. Otherwise a large loan pushes necessities past 50% and the plan collapses.
When the rule does not fit
The 50/30/20 split assumes housing takes well under half your pay. In London, Dublin, Toronto, Sydney, Mumbai or San Francisco — or on a single income with childcare — that assumption is often false. Three honest variants:
- 60/20/20. Housing pushes needs to 60%. Wants shrink to 20% and savings stay at 20%, because the future is the part you cannot borrow back.
- 70/20/10. A high-cost city on an entry salary. Ten percent saved is still a real habit; zero is not.
- Zero-based. Assign every unit of income a job at the start of the month. More work than a percentage, and better for irregular pay.
Variable income needs a different mechanic: budget from the lowest recent month and treat the surplus as savings, rather than budgeting from the best month and praying. The percentage stays useful as a check at year end, not as a monthly instruction.
Make the 20% leave before you see it
A split that depends on willpower loses to one that depends on a standing order. Move the 20% on payday, not at month end, and keep it in an account that is mildly annoying to reach. The same applies to recurring bills: if rent and utilities leave on known dates, the money for them is already spent, whatever the balance says.
The remaining question — what did I actually spend? — is a tracking problem, not a budgeting one. Spendwise keeps the ledger as a local SQLite database on the phone, with one monthly budget that reserves known recurring bills, a reminder at 19:00, and PDF or XLSX export at month end. It does not calculate a 50/30/20 split; set the 50% total as the budget, log as you spend, and compare the report against the plan.
Frequently asked questions
Is 50/30/20 based on gross or take-home pay?
Take-home pay: the amount that actually lands in your account after tax and any pension or payroll deductions. Using gross salary inflates every bucket and makes a budget that looks fine on paper and fails in the bank.
What counts as a need in the 50/30/20 rule?
Rent or mortgage, utilities, groceries, transport to work, insurance, minimum debt payments and necessary medication. Anything you would keep paying while unemployed is a need. A gym you could cancel, a streaming bundle and a second car are wants.
What if my rent alone is more than 50%?
The rule is a starting point, not a law. In a high-cost city, 60/20/20 or 70/20/10 is the honest version: keep a real 20% for savings and debt, and take the shortfall from wants first. Cutting savings to protect wants inverts the priority.
Does the calculator store my income?
No. The arithmetic runs in your browser, nothing is sent anywhere, and the site loads no third-party script. Reloading the page clears everything you typed.
Is the Spendwise app a 50/30/20 budget?
Not directly. Spendwise holds one monthly budget and reserves known recurring bills against it, so the number left is what you can freely spend. Use this page to pick the totals, then set the 50% figure as the monthly budget and log spending against it.