Separating feelings from facts in personal finance.
Think about the last time you made a big money decision. Maybe you were buying a car, deciding whether to rent or buy, or wondering if you should pay off a card before saving anything. Chances are, a lot of voices were in your head. A parent said one thing. A coworker swore by another. A TikTok said you were doing it all wrong.
And somewhere under all of that was a feeling. A knot in your stomach, a little hope, or a vague sense that you should know what to do by now.
Here’s what I want you to know before we go any further: most of us were never taught this stuff. Nobody sat us down in school and said, “Here’s how interest actually works, and here’s how to compare two options.” We picked it up from family, friends, and the internet, and honestly, nobody should have had to figure it out alone.
That’s why Running The Numbers exists.
What “Running The Numbers” Actually Means
The idea is simple. When you’re facing a money decision, there are two things in the room: the facts (the math) and the feelings (everything else). Both matter. I’m not here to tell you your feelings are wrong, because they’re not. They’re information.
But decisions get a lot easier when you can see the two separately. So on this blog, I’ll take a choice that feels big and confusing, grab a calculator (or a spreadsheet, I love a spreadsheet), and walk through the real math in plain English. No jargon without a translation. No shame. Just “here’s what’s actually going on, and it’s usually less scary than it looks.”
Let’s look at a few examples of what I mean. All of these are hypotheticals with made-up round numbers, so you can follow the math easily. Your real numbers will differ.
Example 1: “Renting is throwing money away”
The feeling: Someone in your family told you this years ago, and it stuck. Every rent payment feels like it vanishes.
The math: Say you’re looking at a $300,000 home with a 30-year mortgage at 6.5% (a hypothetical rate, not a quote). The monthly payment for principal and interest comes out to about $1,896. Here’s the quick version of how that breaks down in month one: interest is $300,000 × 6.5% ÷ 12, which is about $1,625. So of that $1,896, only around $271 goes toward actually owning more of the house.
What it means in real life: In the early years, a big chunk of a mortgage payment is interest, which is also money that “goes away.” Add property taxes, insurance, and repairs, and owning has real costs too.
None of this means buying is a bad idea. Owning can be a great choice, and wanting stability or a place that’s truly yours is a completely valid reason. It just means “rent is wasted, mortgage is saved” is too simple to be the whole story. The math lets you decide with your eyes open.
Example 2: “I should keep my extra cash in savings, just in case”
The feeling: Cash in the bank feels safe. Sending it to a credit card feels like it’s gone.
The math: Say you have an extra $200 this month and a $3,000 credit card balance at 24% APR (hypothetical, but not unusual). Here’s the monthly interest on that balance: $3,000 × 24% ÷ 12 = $60. Meanwhile, $200 sitting in a savings account at 4% earns about 67 cents a month ($200 × 4% ÷ 12).
What it means: That card is charging you about $60 a month, roughly a nice dinner out, just for the privilege of carrying the balance. The $200 in savings would earn less than the price of a gumball.
If you already have a savings account with enough of an emergency buffer, it may be time to start paying off the credit card (stay tuned for how to calculate what your emergency savings should be – and why you shouldn’t park it in a normal savings account).
Example 3: “It’s the daily coffee that’s doing me in”
The feeling: Small, frequent purchases feel like the culprit, because you notice them every day.
The math: A $6 coffee, five days a week, for 52 weeks: $6 × 5 × 52 = $1,560 a year. That’s real money, about a month and a half of groceries for some households.
Now compare it to a $550 monthly car payment: $550 × 12 = $6,600 a year. That’s more than four times the coffee.
What it means: The little stuff is easy to see, so it gets the blame, while the big recurring costs quietly do the heavy lifting. If you love your coffee and it is what helps fuel you, keep your coffee! The point is to know which numbers are actually moving your budget, so you can spend your worry where it counts.
Example 4: “I’d rather not look at my balance”
The feeling: Avoiding the number feels like protecting yourself. (If this is you, no judgment at all. Lots of people do this, and it makes total sense.)
The math: Here’s the sneaky part. The number is the same whether you look at it or not. A $4,000 balance is $4,000 on Tuesday and $4,000 on Wednesday, with or without your attention.
What it means: Looking doesn’t change what’s true, but it does give you choices. A number you can see is a number you can make a plan around.
Separating feelings from facts in personal finance
So here’s my invitation. Next time a big money decision lands on your plate, give yourself a moment to separate the two voices. What do I know? What do I feel? You get to listen to both.
Welcome. Let’s Run The Numbers.
This article is for educational and informational purposes only and is not individualized financial, investment, tax, or legal advice. Calculations and examples rely on assumptions, and actual results may differ. Consider your own circumstances and consult a qualified professional before making financial decisions.