# How much you should save each month — and why 50/30/20 fails

> The 50/30/20 rule assumes housing costs that no longer exist. How to reach a realistic savings rate from your own numbers.

Source: https://trybica.com/guides/how-much-to-save-each-month/
Updated: 2026-08-17

---

The 50/30/20 rule says to split net income into 50% needs, 30% wants and 20% savings. It's simple, memorable, and for many people it's arithmetically impossible.

The reason is housing. The rule comes from a context where a home cost around 25% of income. If your rent or mortgage alone takes 40%, the "50% needs" is spent before you've counted utilities, transport and food. That isn't a discipline problem; it's a rule imported from a different cost structure.

That doesn't make it useless. It makes it a target, not a diagnosis.

## Start from the number you have, not the one you should have

The useful question isn't "how much should I save?". It's "how much am I saving now?" — and almost nobody knows the answer.

The savings rate is:

```
(income received − everything that went out) ÷ income received
```

Three details that wreck the calculation if ignored:

**Transfers between your own accounts aren't spending.** Moving €400 into a savings account isn't spending €400. It's the most common distortion and the most misleading — see the [transfers guide](/guides/transfers-are-not-spending/).

**Use an ordinary month.** Bonus months and December aren't representative. Calculate over a month with no events, or across a full twelve, never over a month you picked.

**Count the saving that already happens by itself.** Mortgage capital repayment is saving, not spending — only the interest portion is a cost. Many people save more than they think through this alone.

Do that, and you have a real number. It's usually lower than the expectation and higher than the fear.

## A target that fits real housing costs

Instead of 50/30/20, a scale that works better when housing is heavy:

- **Under 5%** — fragile. One surprise turns into credit. The priority is the first rung of an emergency fund, not optimising anything.
- **5 to 10%** — functional. Reserves build slowly. This is where most people on median income in a city sit.
- **10 to 20%** — healthy. You absorb surprises and make progress.
- **Above 20%** — worth asking whether you're saving toward something or by default. Saving with no destination is a way of postponing decisions.

What matters more than the percentage: **the direction**. A 6% rate that's been rising for a year is a better signal than 15% that's falling.

## Where the percentage points actually are

Raising the savings rate has two levers, and they don't cost the same effort.

**Fixed costs: one decision, permanent effect.** Renegotiating telecoms, switching insurance, cancelling what you don't use. Every euro cut here repeats every month while asking nothing of you. The [forgotten subscriptions guide](/guides/find-forgotten-subscriptions/) is the obvious place to start, and the [fixed costs guide](/guides/cutting-fixed-costs/) handles the larger lines.

**Variable costs: constant attention, effect that unwinds.** Spending less at the supermarket works while you're paying attention, and disappears three weeks later. It's real work with a return that evaporates.

Almost everyone tries the second lever first, because it feels more virtuous. The first is the one that changes the trajectory.

## The step that makes it stick

Automate the transfer to the day you're paid.

Saving what's left at the end of the month doesn't work because nothing is left — spending expands to fill the available balance. Saving first and living on the rest works because spending also adapts to a smaller balance, without conscious effort.

Start with an amount that demands nothing of you: 5% transferred automatically is infinitely better than 15% that never happens. Raise it by a point whenever income rises, and the rate grows without ever hurting.

## Checking without turning it into a project

Once a month, three numbers:

1. **What came in?** Income for the month.
2. **What went out?** Real spending, with internal transfers excluded.
3. **Is the difference bigger than last month?**

That's it. If those three numbers require a spreadsheet and an hour of your Saturday, the exercise won't survive its third month — which is why it's worth having them calculated for you from the accounts you already use. The [weekly money review guide](/guides/weekly-money-review/) describes the smallest habit that holds.