Zero-based budgeting vs. smooth budgeting

Last updated: September 2026 - 6 min read

Zero-based is a popular opinionated method for budgeting originally developed for corporations but popularized by YNAB for personal use. Smooth budgeting is the method introduced by Wellspent.

What each method actually is

Zero-based budgeting:

• Only budget money you have (no projection)
• Assign every dollar to a specific category: savings, goals, groceries etc.
• Assign it every time you get paid

It's worth noting that zero-based budgeting is stricter than its name implies. 50/30/20 is technically assigning every dollar, but it isn't zero-based budgeting in itself, because it doesn't dictate when you assign that money.

Smooth budgeting:

• Estimate your income for the year
• Deduct money for yourself first: savings, debt, goals
• Divide the rest into monthly buckets, like groceries, or yearly ones, like travel

Similarly, 50/30/20 and envelope budgeting aren't incompatible with smooth budgeting. There's a longer write-up of how the number is worked out if you want the mechanics.

Zero-based and smooth budgeting are the stricter frameworks, and they're incompatible with each other. The main differences are: when you assign money (before or after you get paid) and where you start, annual or paycheck, top-down or bottom-up.

Strengths and weaknesses

Both methods have their pros and cons. One isn't necessarily better than the other; they just fit different situations.

Zero-based budgeting is generally more work, because you only plan with the money you have. If you get paid once a month, you plan once a month; if you get paid biweekly, you plan biweekly. The main benefit is that you only ever spend money you actually have. It forces a discipline on you. And if you end up overspending in one category, you have to fix that by moving money around so that you end up back at zero.

Smooth budgeting requires less discipline and less work, but it asks more of your finances. First, it requires fairly predictable income (you can't plan your budget for the year if you have no idea what you'll be earning). It also requires you to be reasonably responsible with money on your own. It won't force a discipline on you when you overspend by $10, but it won't force anything on you when you overspend by $1,000 either. It's also more lenient if you categorized something wrong.

Lastly, smooth budgeting requires a buffer, while zero-based budgeting is a little softer on this. You can still run zero-based without one, but it'll be more work, and you can expect more lifestyle variation (feast when you get paid, famine when you're trying to save). However for smooth budgeting, since you're estimating the money you'll earn, you'll definitely need a buffer to absorb a bad month if it arrives first.

Sinking funds

If you're not familiar with sinking funds, they're essentially buckets that you fund every month or every paycheck for a later large expense (a vacation, a car, a house downpayment). Zero-based and smooth budgeting differ a bit in how they handle these larger expenses.

Let's take a typical case: a $2,400 vacation. With smooth budgeting, you'd plan this proactively as part of your yearly budget. If your spending budget for the year is $40,000, you'd take out $2,400 for the vacation and divide the remaining $37,600, about $3,100 a month, into everyday expenses. With zero-based budgeting, you'd instead move $200 a month into a sinking fund, and once it reaches $2,400 you can take your vacation.

Typically, with smooth budgeting you'd only use sinking funds when the timeline runs beyond a year. With zero-based budgeting, everything beyond the paycheck's timeline is a sinking fund.

Here are a few examples of where each category might sit:

Which method fits better for you

Here are a few situations and the method that fits each of them better.

Paying off debt, with a date in mind

Because there's a deadline, there's not a lot of wiggle room. A bad month close to the date would mess with your goal. A method that puts a hard stop in front of you every month will push harder than one that averages. Zero-based

Just lost a job, four months of runway, no room for waste

Precision isn't overhead when the margin is close to zero. It's necessary. Knowing exactly which category the next $60 comes out of is worth the daily effort here. Zero-based

Freelancing, two years of history, some savings but irregular paychecks

The income estimate is credible and the buffer exists, which are the two things smoothing needs. Re-planning every time a client pays late is pure churn. Smooth

Full-time employee, no debt, and an emergency fund ready

Nothing here needs precision. What's wanted is a number to check against every few weeks and an early warning if it drifts. Smooth

Paycheck to paycheck, income varies, no buffer yet

Smoothing can't work because nothing absorbs the variance. Zero-based will raise an alarm most weeks about a gap there's no money to close. The real problem is timing, not method: line the bills up against the paydays, and build the smallest buffer you can. The method comes after. Neither, yet

Other methods

We briefly talked about 50/30/20 and envelope budgeting, which are fairly standard concepts and which work with both of the methods described here. There are some others out there, like Ramit Sethi's Conscious Spending Plan or anti-budgeting. Those last two are a little less defined than smooth budgeting, but similar in spirit: you don't track every dollar, and you pay yourself first. Smooth budgeting goes a little further by taking a yearly perspective, which helps with irregular expenses like travel or health.

Conclusion

The zero isn't the distinguishing feature since both methods end with every dollar assigned. What separates them is when you assign it and where you start, and those two settings decide everything else: how often you re-plan, whether a lean month is a decision or a non-event, and how much the method leans on a buffer instead of on you.

So the useful question isn't which one is better. It's whether your income is predictable enough to forecast, whether you have a buffer, and whether you want a method that stops you or one that stays out of your way.

Hi, I'm Emilien, the founder of Wellspent. If anything here is out of date or wrong, feel free to let me know.