Calculate cash flow

Estimate monthly and annual rental cash remaining after vacancy, finance, management, and running costs.

freeworks offlinenothing uploaded
ToolCash Flow Calculator
Input
Output
—
Put this on your own site

The frame below runs the same code as this page, in the reader's own browser. Nothing is sent to us, and nothing is sent to you.

Pick a dark background and the text and panels follow it, so the frame stays readable on a dark page.

Preview

How it works

Full rent is reduced by the vacancy percentage before management commission is calculated. Mortgage payment, maintenance, insurance, commission, and other costs are then subtracted; every optional cost defaults to 0 so no local expense is invented.

Formula
collected rent = full rent × (1 − vacancy rate)
cash flow = collected rent − all monthly costs
  • The management percentage applies only to modeled rent actually collected.
  • Annual cash flow is the resulting representative month multiplied by 12.

Worked example

A flat renting at 1,200 a month
With a 500 mortgage payment, running costs and a letting agent on 10%
Input
											Monthly rent: 1200
Vacancy rate percent: 5
Monthly mortgage payment: 500
Monthly maintenance: 50
Monthly insurance: 30
Management fee percent: 10
Monthly other costs: 20
Output
												Effective monthly rent: 1140
Management fee amount: 114
Total monthly costs: 714
Monthly cash flow: 426
Annual cash flow: 5112

When to use this

Buy-to-let underwriting, landlord monthly accounts, and property-management budgets combine void allowance with mortgage, repairs, insurance, and agent fees.

Edge cases

  • At 100% vacancy, collected rent and percentage management fee both become 0 while fixed costs remain.
  • If monthly costs exceed collected rent, cash flow remains negative instead of being clamped to 0.
  • Management percentage is applied after vacancy, so no commission is charged on modeled uncollected rent.