Maintenance Cost Calculator Formula
Understand the math behind the maintenance cost calculator. Each variable explained with a worked example.
Formulas Used
Estimate (% of Value)
pct_estimate = pct_methodEstimate (Per Unit)
unit_estimate = per_unit_methodMonthly Reserve (Higher)
monthly_reserve = (pct_method > per_unit_method ? pct_method : per_unit_method) / 12Variables
| Variable | Description | Default |
|---|---|---|
property_value | Property Value(USD) | 350000 |
maintenance_pct | Annual Maintenance Rate(%) | 1.5 |
num_units | Number of Units | 2 |
per_unit_annual | Per-Unit Annual Budget(USD) | 2500 |
pct_method | Derived value= property_value * maintenance_pct / 100 | calculated |
per_unit_method | Derived value= num_units * per_unit_annual | calculated |
How It Works
Estimating Maintenance Costs
Two common methods for budgeting maintenance and repairs:
Percentage-of-Value Method
Annual Maintenance = Property Value x Rate%
Typical range: 1-2% of property value annually
Per-Unit Method
Annual Maintenance = Number of Units x Per-Unit Budget
Typical range: $1,500-$3,500 per unit per year
Use the higher estimate for conservative budgeting
Worked Example
A $350,000 duplex using 1.5% value rate and $2,500 per unit budget.
- 01Percentage method: $350,000 x 1.5% = $5,250
- 02Per-unit method: 2 x $2,500 = $5,000
- 03Higher estimate: $5,250
- 04Monthly reserve: $5,250 / 12 = $437.50
Frequently Asked Questions
Which method should I use?
Use the higher of the two for conservative budgeting. The percentage method works better for higher-value properties, while the per-unit method is more practical for multifamily properties.
Does property age affect maintenance costs?
Absolutely. Newer properties (under 10 years) may need only 0.5-1% of value, while older properties (over 30 years) may require 2-3% or more as systems age and need replacement.
What is the difference between maintenance and CapEx?
Maintenance covers routine repairs (leaking faucets, HVAC servicing). Capital expenditures (CapEx) are major replacements (new roof, furnace replacement) that extend the useful life of the property.
Ready to run the numbers?
Open Maintenance Cost Calculator