Most buyers look at principal and interest only when determining monthly payment amounts. The real number also includes taxes, insurance, HOA or condo dues, utilities, and basic upkeep. This guide gives you a simple worksheet, a quick way to pull each figure, and a worked example you can copy.

Copy and use worksheet

Start with your lender estimate

  • Principal and interest: ________
  • Interest rate and loan type noted: ________

Add predictable costs

  • Property taxes (annual divided by 12): ________
  • Homeowners insurance (annual divided by 12): ________
  • Mortgage insurance if under 20 percent down: ________
  • HOA or condo dues: ________

Add usage based costs

  • Electric average: ________
  • Water and wastewater average: ________
  • Gas average if applicable: ________
  • Internet: ________

Add ownership costs

  • Routine maintenance set aside. Use 1 percent of purchase price per year divided by 12: ________
  • Lawn and pest service if used: ________
  • Commute estimate if it changes your fuel or tolls: ________

Your real monthly total: ________

How to get each number in five minutes

1) Property taxes

  • Use last year’s tax bill for the address. Divide by 12.
  • If the home will not carry a full homestead exemption yet, add a buffer for year one.
  • Ask your lender to model taxes both with and without homestead so you see the range.

Helpful on our site: Property Taxes in Central Texas: How to Protest Your Appraised Value

2) Homeowners insurance

  • Request a quote now. Note coverage, roof age, and wind hail deductible.
  • If the roof is older or has prior claims, expect a higher premium.
  • Divide the annual premium by 12.

3) Mortgage insurance

  • If your down payment is under 20 percent, ask your lender for the monthly PMI estimate at your credit score and loan type.
  • Plan how and when PMI can drop off.

4) HOA or condo dues

  • Use the seller’s disclosure or management company summary for the current monthly dues.
  • Ask about transfer and initiation fees for closing day planning.

5) Utilities

  • Request the last 12 months of electric and water bills from the seller.
  • Take the average of the highest three months for a summer comfort test.
  • Add gas if applicable and your preferred internet plan.

6) Routine maintenance

  • Use the rule of thumb. One percent of purchase price per year divided by 12.
  • Older homes or pools may need a larger set aside.

Worked example you can copy

Buyer targets a home at 525,000 dollars. Conventional loan with 10 percent down. Sample numbers only.

Principal and interest

  • Quoted monthly at current rate: 3,000

Predictable costs

  • Taxes: 10,200 per year divided by 12 = 850
  • Insurance: 2,100 per year divided by 12 = 175
  • PMI estimate from lender = 140
  • HOA = 55

Usage based costs

  • Electric average = 180
  • Water and wastewater average = 95
  • Internet = 70

Ownership costs

  • Maintenance set aside. One percent of 525,000 per year is 5,250. Divide by 12 = 438
  • Lawn and pest service = 65

Real monthly total = 3,000 + 850 + 175 + 140 + 55 + 180 + 95 + 70 + 438 + 65 = 5,068

The real monthly is about 2,000 above principal and interest in this example. Now you can adjust price or choose a neighborhood with lower taxes or dues.

Three common mistakes to avoid

  1. Forgetting the first year tax change. If the seller had a full homestead and you will not until the next calendar year, plan for a higher first year escrow.
  2. Ignoring roof age and deductible. A lower premium with a high wind hail deductible can be risky if you need a claim.
  3. Skipping utility history. Summer bills can be much higher than the annual average.

House in mind already?

Send us the address and your worksheet! We’ll turn it into a clear “offer number” before you tour. Use our Free Resources for Buyers to keep quotes, bills, and worksheets in one place.