Skip to main content
Calcimator

Absorption Rate Calculator

Calculate monthly sales absorption rate, months of supply, and project sellout timeline.

About this calculator

The Absorption Rate Calculator tracks how quickly a residential or commercial project sells relative to the units still available. The Monthly Absorption Rate is not derived by averaging historical closings inside the calculator — it is simply the Sales per Month figure you enter, carried through and rounded to two decimals. Months of Data must be a positive number for the calculator to run at all, but changing its value does not change the absorption rate, either timeline, or any dollar figure; the calculator trusts that you already averaged your own sales history before typing that monthly figure in.

From that single rate, two different timelines are derived that are easy to confuse: Months of Supply divides only Current Inventory (unsold units currently listed) by the absorption rate, while Sellout Timeline divides the full Total Project Units by the same rate, so it reflects the whole project's remaining life rather than what is on the market today. Average Sale Price feeds only the revenue figures and has no effect on either timeline. The calculator assumes a constant, unchanging pace of sales — it does not model seasonality, contract cancellations between reservation and closing, price appreciation, incentive-driven sales bursts, or the natural slowdown many projects see as inventory thins near sellout.

Inputs

$
months

Results

Monthly Absorption Rate

4 units/mo

Sellout Timeline

20 months

Months of Supply6.25
Sellout (Years)1.67
Annual Absorption48 units
Annual Absorption %60%
Annual Revenue$16,800,000.00
Total Project Revenue$28,000,000.00
How to Use This Calculator
  1. Enter Total Project Units or lots and Sales per Month based on comparable projects or market data.
  2. Set Average Sale Price per unit and Current Inventory of unsold units on the market.
  3. Enter Months of Data used to calculate the absorption rate for statistical reliability.
  4. Review Monthly Absorption Rate — the pace at which the market is absorbing your product type.
  5. Check Sellout Timeline in months and years to plan your development schedule and financing.
  6. Compare Months of Supply against historical norms — under 6 months is a seller's market.

How the result changes with Sales per Month

Sales per MonthMonthly Absorption RateSellout Timeline
22 units/mo40 months
33 units/mo26.67 months
66 units/mo13.33 months
1010 units/mo8 months

What each input means

Total Project Units
Total units or lots in the project.
Sales per Month
Average number of units sold per month.
Average Sale Price
Average sale price per unit.
Current Inventory
Currently available unsold units on the market.
Months of Data
Number of months used to calculate the absorption rate.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Total Project Units = 80, Sales per Month = 4, Average Sale Price = 350000, Current Inventory = 25 = 5 input(s) provided
  2. Calculate Monthly Absorption Rate
    Monthly Absorption Rate
    4 = 4
  3. Calculate Sellout Timeline
    Sellout Timeline
    20 = 20
  4. Calculate Months of Supply
    Months of Supply
    6.25 = 6.25
  5. Calculate Sellout
    Sellout
    1.67 = 1.67

Engine last updated . Checked against 1 independently-derived test — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.

Frequently Asked Questions

Why doesn't changing Months of Data change the Monthly Absorption Rate?

Months of Data is a validity gate, not an averaging window: the calculator returns 0 whenever it is zero or negative, but any positive value produces the exact same result. The Monthly Absorption Rate always equals the Sales per Month figure you typed, rounded to two decimals — the calculator trusts you already averaged your sales history before entering that number.

What's the difference between Sellout Timeline and Months of Supply?

Months of Supply divides only Current Inventory — the units presently listed and unsold — by the absorption rate, answering how long today's listed inventory would last at this pace. Sellout Timeline instead divides the entire Total Project Units by the same rate, answering how long the whole project takes to sell out from scratch, including units not yet released to market.

Does raising the Average Sale Price shorten the Sellout Timeline?

No. Average Sale Price only feeds the two revenue figures, Annual Revenue and Total Project Revenue, and has zero effect on Sellout Timeline or Months of Supply, both of which depend solely on unit counts and the absorption rate. A higher price increases projected revenue without changing how fast units actually move off the market.

What counts as strong absorption for a new development?

There is no universal number — a fast-selling urban condo tower and a rural lot subdivision have very different normal paces. This calculator reports your project's actual Monthly Absorption Rate so you can compare it against comparable projects or your own historical benchmarks, rather than measuring you against one industry-wide target.

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Land Development

Development Pro Forma Calculator

Create a development pro forma with revenue, costs, profit, and ROI projections.

Land Development

Lot Yield Calculator

Calculate the number of buildable lots from raw acreage after deducting roads, open space, and unusable land.

Land Development

Entitlement Timeline Calculator

Estimate months from raw land to building permit through the entitlement process.

More in Real Estate & Property.