Divorce Budgets 101: How to Build a Post-Separation Spending Plan

When I left my marriage, I had no idea what my new budget was going to look like.

I knew what “our life” cost. I knew the mortgage payment. I knew roughly what we spent on groceries and childcare. But I didn’t know what my life would cost, because I hadn't started it yet!

I remember sitting at my kitchen table with a blank spreadsheet, feeling equal parts terrified and determined. I wasn’t just building a budget. I was building the financial foundation of my new life.

Here's how I did it.

Step 1: Start With Your New Reality — Not Your Old Life

Throw out your old budget. That life was built on shared expenses, shared income, and shared risk. Your new life is different, and you need to plan accordingly.

You need to understand:

• What money is coming in

• What money is going out

• And what financial responsibilities are now yours alone

Your income may now include:

• Employment income

• Child support (received or paid)

• Spousal support (received or paid)

• Government benefits (like the Canada Child Benefit)

• Other sources of income

One of the biggest mistakes I see people make is either overestimating or underestimating what’s truly available to them. Support payments feel abstract until they actually start arriving — or leaving — your account. Use real numbers, not hopeful ones. Be sure you know which sources of income are taxable and which aren't - this can make a huge difference to your bottom line.

Step 2: Build Your Spending Plan From Scratch

Start with your fixed expenses:

• Housing (rent or mortgage)

• Property taxes

• Insurance

• Utilities

• Phone and internet

• Car payments, insurance, and fuel

• Childcare

• Debt payments

Then your variable expenses:

• Groceries

• Kids’ activities

• Clothing

• Medical expenses

• Personal spending

It took me a while after my divorce to find my real budget. Some expenses went down. Others went up dramatically. Groceries went down. But housing, insurance, and childcare became heavier burdens because there was no longer anyone to share them with.

Step 3: Understand Your Parenting-Related Financial Responsibilities

This is where post-divorce budgets get more complex. Beyond basic living costs, there are child-specific financial obligations that often aren’t part of traditional budgets.

These may include:

• Extra-curricular expenses (shared special expenses like sports, childcare, or medical costs)

• Summer camps

• School fees and supplies

• Clothing for growing kids

• Post-secondary savings contributions (if agreed upon or ordered)

These costs can be irregular and unpredictable. And you need to know how these are going to be split with your coparent. I recommend creating a monthly “children’s expenses” sinking fund — even if the actual expenses don’t occur every month. Because they will come. They always do.

You may also be responsible for post-secondary savings for your kids, or costs when the time comes (whether you've saved or not). It's typical for separation agreements to address this, and it can also be ordered by a court. Ensure you know what you're going to be on the hook for, and plan accordingly.

Step 4: Don’t Forget Your Future — Retirement Matters More Now

This was the hardest mental shift for me. When you’re married, retirement savings often happen quietly in the background. Pension contributions. Shared investments. And with a dual income household, it feels manageable. After divorce, you're likely to have less money to contribute to retirement, but it matters more, because you're now solely responsible for your own financial future.

Even small monthly contributions matter. The goal isn’t perfection. It's consistency.

Step 5: Accept That This Is a Living Document

Your first post-divorce budget will not be perfect. Mine certainly wasn't. I reworked it every few months until I found my groove. Unexpected expenses surfaced. Support payments changed. Income evolved.

Your budget isn’t a fixed artifact. It’s a tool that evolves with you. A living tree of sorts.

Be prepared to revisit your budget often as your circumstances change.

Bottom Line

The scariest part of divorce, financially, isn’t the numbers themselves. It’s the uncertainty.

Once you can see your full financial picture — clearly, honestly, without avoidance — something shifts. You realize you’re not powerless. You’re just rebuilding.