How much does a no-buy year actually save?

Take what you spend in a normal week in the categories you are banning, multiply by 52, then subtract what replaces it and any reward you planned. That is your honest number. For a no-buy on a few everyday categories, it usually lands somewhere between a few hundred and a few thousand dollars over a year.

The gross figure — the one in the first half of that sentence — is what most calculators show you, and it is always too high. Below is the table for the gross figure, the three leaks that shrink it, and a four-line worksheet that gets you to the number that actually reaches savings.

The table: what a daily or weekly leak adds up to

Start with the daily figure if your leak is small and frequent — coffee, snacks, delivery fees. Start with the weekly figure if it arrives in baskets — clothes, beauty, the online cart.

These numbers are why no-buy challenges exist. Almost nobody would sign off on a $1,825 purchase of coffee, and almost everybody buys it, five dollars at a time.

How to find your weekly leak

Do not guess it. People consistently underestimate small daily spending and overestimate occasional big purchases, which is the wrong way round for this.

Open your last sixty days of transactions. Add up everything in the categories you plan to ban — takeout, coffee out, clothes, whatever is on your list — and divide by eight and a half. That is your average week. If one week contained something unusual, like a holiday, leave it out and divide by seven and a half instead.

For context, here is what the average US household spent in 2024 in the categories that most no-buy lists include, from the Bureau of Labor Statistics Consumer Expenditure Survey:

Category	Average household, 2024	Per week
Food away from home	$3,945	about $76
Apparel and services	$2,001	about $38
Personal care products and services	$978	about $19
Alcoholic beverages	$643	about $12

These are averages across every kind of household, not targets — and not all of any category is optional. A haircut is personal care. A winter coat is apparel. But the table shows why food away from home is the first line on most lists: it is the largest optional category most households have.

The three leaks that shrink the number

The gross figure assumes that every dollar you do not spend in a category stays put. It does not. Three things take a share of it, and knowing them in advance is what makes the estimate honest.

1. Substitution

Banning a category does not remove the need it was serving. Ban takeout and you still eat, so the grocery bill goes up a little. Ban café coffee and you buy beans. The substitute is almost always far cheaper — a $15 delivery meal becomes $4 of groceries — but it is not free.

For categories that replace a need, like food and drink, count roughly what the substitute costs and take it off. For categories you simply stop, like new clothes or decor, the substitute is usually nothing, and you keep close to the full amount.

2. The rebound

Two versions. The planned one is the reward at the end — the dinner, the one big purchase — and it is a good idea; a challenge with a reward is a challenge people finish. Take it off the number in advance so it does not feel like a loss.

The unplanned one is the splurge in the week after the challenge ends, when a month of “not yet” turns into a basket. It is common enough to plan for: end the challenge with a wishlist review, not an open browser, and buy only what has survived the wait.

3. The money that never moves

This is the largest leak and the easiest to fix. A no-spend day produces no visible result. Nothing happened, so nothing shows up — the money you did not spend just sits in your current account, and a checking account is where money goes to be spent on something else.

If the kept money does not move, a successful month can end with almost nothing to show for it, and that is the single most common reason people do not do a second month. The fix is mechanical: once a week, move the week’s kept amount to a separate savings account. The money is only saved once it has moved.

The four-line worksheet

Write this down — on the back of a tracker, in a note, anywhere you will see it again.

1. My weekly leak in the categories I am banning: $___
2. What replaces it each week (groceries instead of takeout, home coffee instead of café): $___
3. Line 1 minus line 2, times the number of weeks: $___
4. Minus the reward I have planned: $___

Line four is your honest number. Line one times the weeks is the number you will see on social media.

Three worked examples

These are illustrations of the method, not typical results.

The takeout leak. $60 a week on delivery. Gross for a year: $3,120. Cooking instead adds about $20 a week to groceries, or $1,040 a year. Planned reward: a $150 dinner out at the end. Honest number: $1,930.

The coffee leak. $6 a day, five working days a week, is $30 a week. Gross for a year: $1,560. Good coffee at home costs about $5 a week, or $260. No reward planned. Honest number: $1,300 — still a real figure, from one habit.

The online basket. $180 a month on clothes and marketplace orders, mostly things that arrived and were never thought about again. Gross for a year: $2,160. No substitute, because nothing needed replacing — except one pair of jeans that wore through, replaced like-for-like for $60. Honest number: $2,100, which is close to gross, because stopping a habit with no underlying need keeps nearly all of it.

Notice the pattern. Food leaks shrink by somewhere between a sixth and a third once the substitute is counted. Shopping leaks barely shrink at all. That is worth knowing when you choose what goes on your list.

No-buy, low-buy, and the year you actually finish

A strict no-buy produces the biggest number on paper. A low-buy, which caps a category instead of banning it, produces a smaller one — and tends to last. A no-buy abandoned in March keeps three months of the leak. A low-buy at two-thirds of the saving, run for twelve months, keeps far more.

If you are unsure which to run, use the worksheet for both. Then pick the one you believe you would still be doing in June.

Let something else do the counting

The money you did not spend is invisible unless something adds it up. That is the job a tracker does on paper and the job NoBuy does on your phone: one tap at the end of the day, and the money you kept goes onto a running total beside the streak, so a quiet Tuesday with nothing bought still counts for something you can see. Moving that total to savings each week is still yours to do, and it is the step that turns the number into money.

The short version

Weekly leak, minus what replaces it, times the weeks, minus the reward. Use your own statement, not a guess. Expect food categories to shrink by up to a third once you count groceries; expect shopping categories to keep almost all of it. And move the money every week — because the saving that stays in your checking account is the saving that disappears.