How Accurate Is Your Retirement Spending Estimate, Really?

If you ask a couple what they spend in a year, most will answer quickly. A number comes to mind and sounds reliable, but it usually isn’t.

That number is their retirement spending estimate, and most retirement plans are based on it. The problem is, for most couples, the estimate is too low. Sometimes it is not just a little low. It is low enough to change the whole plan.

The issue isn’t bad math. It is about what gets left out.

Imagine this scenario

Imagine a couple in their late fifties, both still working, sitting down on a Sunday afternoon to figure out what retirement might cost. They look at their bank statements, add up the mortgage, utilities, groceries, insurance, and a few subscriptions. They come up with a monthly number, multiply it, and feel confident about their estimate.

But they didn’t include the roof that is 18 years old, the car that might need replacing in the next decade, or the trip they have talked about for years. There is also that year, and there almost always is one, when the water heater, the transmission, and a dental crown all need attention within a few months.

None of those expenses made it into their spreadsheet. They rarely do.

The first retirement spending estimate most people make

Most spending estimates are based on what is easy to see. Recurring bills show up every month, so they are easy to track and trust. Groceries, utilities, insurance premiums, mortgage or rent. Add them up, and the total feels complete.

But it isn’t complete. It only covers the spending that happens on a regular schedule.

Irregular costs don’t appear on monthly statements. They might come up every few years, once a decade, or just occasionally with no warning. Because they are unpredictable, it is easy to forget about them until they happen, and when they do, they are often big.

A plan based only on recurring expenses is already missing something important. It might work for years, but when a big cost comes up, the plan has to handle something it wasn’t designed for.

The costs that don’t appear every year

Consider the expenses that don’t fit into a monthly budget. A roof lasts for decades, then needs replacing. A car is replaced every several years, not every month. A big trip, if you take one, often costs more than a month’s living expenses. And then there is the year when something breaks. Anyone who has owned a house or car for a while knows that year. It always seems to come at the worst time.

These costs are real. They aren’t rare emergencies. They are actually somewhat predictable, just not on a monthly schedule. A retirement spending estimate that leaves them out isn’t wrong because of bad math. It is wrong because it only includes the easy-to-count expenses.

Why the estimate is usually too low, not just inaccurate

This pattern happens for a simple reason. When couples estimate their spending, they usually think about a normal month. A month without car repairs, big trips, or anything unusual. Just an average month.

That is a reasonable way to think, but it is also why the estimate is almost always too low. Normal months, by definition, don’t include high, irregular costs. When you average only those months, you miss the years with a new roof, a transmission, or a big trip.

Costs also tend to go up over time, and retirement can last 25 years or more. An estimate based on today’s normal month might not work over that long stretch, even before you add in irregular costs. On the income side, Social Security, under the law as currently written, is just one part of the picture. It is not something to rely on completely, since the rules can change in the future.

None of this means a couple made a mistake. It just means their estimate answered an easier question than the one that really matters.

How this plays out in the Triangle area

The general issue is the same everywhere, but some details are local and matter if you plan to retire here.

Home values in Apex, Cary, and the wider Triangle have gone up in recent years. This affects retirement plans in two ways. Wake County reassesses property values regularly, and property taxes usually rise with those values, so your tax bill isn’t as fixed as you might think. Homeowners insurance has also increased. Neither of these costs shows up in a typical month, but both can rise over the course of a long retirement.

There is another local factor. Many people retire to the Triangle from more expensive areas. Costs here are still lower by comparison, but that can be misleading. It is easy to see a lower number than you paid up north and assume it will stay the same. Lower doesn’t mean fixed. Taxes, insurance, and home upkeep can all increase here too.

If you plan to retire here, it is worth asking what your tax bill, insurance, and upkeep might look like in 15 years, not just what they cost today.

One estimate can lead to two very different plans

A retirement spending estimate isn’t just a number on a page. It is the foundation for everything else. Withdrawal amounts, tax planning, how quickly you use your savings, and even when to start Social Security, under the law as currently written. All of these decisions depend on that one figure.

When the estimate is too low, the plan built on it looks better than it really is. Projections go further, savings seem to last longer, and on paper, the math works.

Then the roof needs replacing, the trip finally happens, or the year something breaks arrives right on time. The plan has to cover a cost it never planned for. Sometimes that means dipping into savings faster than you wanted. Sometimes it means cutting back somewhere else for a year. Neither is a crisis by itself, but a plan that keeps getting surprised by predictable costs isn’t really doing its job.

This is the hidden cost of an estimate that is too low. It doesn’t show up as an obvious mistake, but years later, you notice the plan bending more often than it should.

Questions worth considering

These are the questions a real retirement spending estimate should answer. Most people can’t answer them right away, and that is exactly the point.

• When did you last replace your roof, and when might you need to again?
• What did your last big trip actually cost once everything was added up?
• How much did your last “something broke” year end up costing you?
• Are irregular costs built into your annual number, or left out entirely?
• If your car needed replacing next year, would that come from a plan or from a scramble?
• If costs keep rising over the next 20 or 25 years, what happens to a number based on this year alone?

What it looks like to work through this

This isn’t about just coming up with a bigger number and moving on. It takes more time. We look at spending over several years, not just one, so irregular costs are included instead of ignored. We separate monthly expenses from those that happen every few years, so both are counted properly. We also ask what a big trip, a roof, or a car might really cost, instead of leaving those out.

Our Apex, North Carolina office helps pre-retirees and business owners across Raleigh, Durham, and Chapel Hill with this process, and we include the local costs mentioned above. For questions about taxes or legal matters, we refer clients to their CPA or attorney, since those issues go beyond what a spending estimate can cover.

The goal isn’t to find a perfect number. There isn’t one. The goal is to have a number that actually includes years with a new roof, a car, a trip, or a year when something breaks, rather than quietly assuming those years won’t happen.

Find out where you stand

If you want a place to start reviewing your own numbers, the Retirement Confidence Checklist covers the categories most estimates miss, including income, taxes, investment risk, timing, and how everything fits together. Download the Retirement Confidence Checklist.