I'm a Financial Planner: These 4 Spending Mistakes Can Derail Your Retirement Plan
Many plans focus on how much has been saved, but it's how much you spend that ultimately determines whether your plan works.
Retirement planning often starts with a simple question: How much do I need to retire?
You'll often hear answers framed around a single number. One million dollars. Two million. Maybe more.
That question, while important, can lead you in the wrong direction. Retirement success isn't defined by how much you have, but by how much you spend.
From just $107.88 $24.99 for Kiplinger Personal Finance
Become a smarter, better informed investor. Subscribe from just $107.88 $24.99, plus get up to 4 Special Issues
Sign up for Kiplinger’s Free Newsletters
Profit and prosper with the best of expert advice on investing, taxes, retirement, personal finance and more - straight to your e-mail.
Profit and prosper with the best of expert advice - straight to your e-mail.
Your portfolio, rate of return and savings habits all matter, of course. But your spending shapes how long your money lasts, how much flexibility you have and what your retirement lifestyle looks like.
It's often one of the most overlooked parts of the planning process.
Here are four common spending mistakes that can quietly derail an otherwise solid retirement plan and how to avoid them.
About Adviser Intel
The author of this article is a participant in Kiplinger's Adviser Intel program, a curated network of trusted financial professionals who share expert insights on wealth building and preservation. Contributors, including fiduciary financial planners, wealth managers, CEOs and attorneys, provide actionable advice about retirement planning, estate planning, tax strategies and more. Experts are invited to contribute and do not pay to be included, so you can trust their advice is honest and valuable.
1. Relying on estimates instead of actual spending
For many, a common starting point when thinking through their expenses sounds something like this: "I think we spend about $7,000 a month."
The problem is that this number is often more of an estimate than something based on actual spending.
When you take the time to review your spending in detail, the results are often different than expected, sometimes meaningfully so.
Even small gaps between estimated and actual spending can compound over time. Over a 25- or 30-year retirement, those differences can significantly change the outcome of your plan.
A better approach is to work from real data. Start by reviewing your last three to six months of credit card and bank statements to determine where your money is going. Identify patterns and revisit those assumptions as retirement approaches, when spending habits are likely to shift.
There are many budgeting tools that can help organize this process, but even a simple breakdown of your spending can provide a much clearer and more reliable starting point than a rough estimate.
2. Overlooking one-time and irregular expenses
Many retirement plans are built around a monthly or recurring spending plan, but some of the most significant expenses don't show up monthly.
- Replacing a car every several years
- A new roof or major home repair
- Helping children or grandchildren
- Larger travel experiences
Because these costs are irregular, they're easy to overlook. But over time, they can have a meaningful impact on your plan. They also tend to show up at inconvenient times.
A large expense during a market downturn, for example, can force withdrawals at less favorable moments, which can have a lasting effect on your portfolio.
A better approach is to plan for these expenses in advance. Start by identifying the larger costs you're likely to face over time and estimate when they might occur.
Even rough assumptions, such as replacing a car every seven to 10 years or setting aside funds for home maintenance, can improve the accuracy of your plan.
You don't need perfect precision (no one has a crystal ball for when these expenses will show up). But treating these expenses as expected, rather than occasional surprises, can help create a more realistic and resilient retirement plan.
3. Assuming your spending will stay the same every year
Another common assumption is that spending remains constant throughout retirement, increasing only with inflation. In reality, spending tends to evolve.
Based on retirement spending research, many retirees tend to spend more in the early years, traveling, pursuing hobbies and taking advantage of their time and health (every day in retirement is a Saturday).
Over time, spending tends to decrease as those activities slow down. Perhaps you're not traveling as much or as adventurously as in your early retirement years.
Later in life, it's likely to shift again, with health care and support-related expenses becoming a larger component, while discretionary spending might trend down. These phases are sometimes described as the go-go, slow-go and no-go years.
A flat spending assumption can distort projections. It might lead you to believe you need more than necessary early, or cause you to underestimate costs that could arise later in life. In both cases, the result is a retirement plan that doesn't fully reflect how spending actually unfolds.
A more realistic approach is to think about spending in stages. Estimate what your lifestyle might look like in the early years of retirement, how it could change over time and where costs might increase later on.
Even simple adjustments to reflect these phases can make your plan more accurate and easier to manage.
4. Treating all spending as equal
Not all expenses carry the same weight, even if they show up in the same monthly total.
Some costs are essential. Housing, food, insurance and health care are the foundation of your plan. These are the expenses that need to be covered regardless of market conditions or what the economy is doing.
Others fall into a more flexible category. Travel, dining out, hobbies and certain lifestyle choices might be meaningful parts of your retirement, but they can also be adjusted if needed.
When everything is grouped into a single number, it becomes difficult to see where that flexibility exists.
More important, it becomes harder to know how to respond if conditions change. This isn't just about seeing where your money goes; it's about knowing what you'd do if you needed to make an adjustment.
By separating essential from discretionary spending, you create a clearer picture of your baseline needs and your optional spending. That distinction can make your plan more resilient, especially during periods of market volatility when having the ability to adjust even modestly can help keep a long-term plan on track.
Looking for expert tips to grow and preserve your wealth? Sign up for Adviser Intel, our free, twice-weekly newsletter.
How better spending assumptions can change a plan
In my work at Boldin, I often see how small changes in how people think about spending can significantly improve their confidence in a plan.
One couple I worked with, both in their early 60s, initially estimated their retirement spending at about $9,000 per month. It was a number they had set years ago and had not revisited the details. It just felt right to them. As retirement approached, they decided to take a closer look.
Instead of relying on a single estimate, they took the time to break their spending into categories. Their essential expenses, including housing, utilities, food and insurance, came out to about $8,000 per month.
From there, they added discretionary spending, including travel, dining out and hobbies, which brought their early retirement spending closer to $11,000 per month.
They also accounted for larger, irregular expenses that weren't part of their original estimate — replacing cars and future home repairs. Just as important, they adjusted their plan to reflect different phases of retirement. They weren't planning trips to Bora Bora or European excursions in their 80s, so they scaled their spending accordingly over time.
The result wasn't just a revised number, but a clearer understanding of how their retirement could unfold and where they had flexibility if conditions changed.
That clarity led to something just as important as the numbers themselves: Confidence. Instead of wondering whether they had "enough," they could see the trade-offs. If markets declined, they knew where they could adjust. If things went better than expected, they had room to spend more.
Get this number right, and everything else becomes clearer
Spending is not just another input in your retirement plan. It's one of the key drivers of whether your plan succeeds.
When you measure it accurately, account for how it changes over time and build flexibility into your plan, everything else becomes easier to evaluate. Investment decisions, withdrawal strategies and tax planning all become more clear and intentional.
Retirement planning is not about guessing a number and hoping it works. It's about aligning your spending with the life you want to live and adjusting as that life evolves.
Get that right, and the rest of your plan has a much stronger foundation.
Related Content
- 16 Retirement Mistakes You Will Regret Forever
- 9 Things You Need for a Complete Retirement
- The Retirement Spending Mistake Even Careful Savers Make (and What to Do Instead)
- 5 Habits to Help Make Your Retirement Planning Highly Effective
- 4 Smart Ways to Use Your Tax Return for Financial Planning
Profit and prosper with the best of Kiplinger's advice on investing, taxes, retirement, personal finance and much more. Delivered daily. Enter your email in the box and click Sign Me Up.

Michael Pappis, a CFP® professional and IRS Enrolled Agent, is a financial planner and educator with more than a decade of experience helping people make informed, confident decisions about their financial lives. Since entering the financial services industry in 2013, he has advised a wide range of clients on retirement income planning, tax strategy, equity compensation and long-term financial modeling. Michael has worked in both traditional wealth management and the FinTech space, giving him a unique perspective on how people can use planning tools and clear decision frameworks to navigate their financial lives more effectively.