Monthly sales pace
Closed sales during the window ÷ number of months in that window.
Absorption rate in real estate
Calculate sales absorption and months of supply, check the inputs, and avoid mistaking a faster ratio for stronger demand.
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What absorption rate measures
Residential absorption rate compares the monthly pace of completed home sales with the homes currently available for sale. Expressed as a percentage, it is monthly sales divided by active inventory, multiplied by 100.
Reverse the division and you get months of supply. That estimates how long the inventory would last at the chosen sales pace, assuming no new listings. Neither figure predicts when a particular home will sell.
This guide uses the monthly sales-to-inventory convention described by Transactly. Terminology varies: some tools call a time-to-clear measure an absorption rate. Check the units before comparing two reports.
For offices, industrial properties or rental units, commercial net absorption answers a different question: how much occupied space changed, rather than how quickly for-sale homes are trading.
Calculate the monthly ratio
Start with closed sales, not just signed contracts. Count homes available for sale using your provider's active-listing definition. Keep pending listings separate unless the report explicitly defines its inventory otherwise.
Monthly absorption percentage
Monthly sales pace ÷ active inventory × 100.
Months of supply
Active inventory ÷ monthly sales pace.
For positive, matching inputs, months of supply also equals 100 divided by the absorption percentage. Use the percentage number, such as 20, not the decimal 0.20, in that shortcut.
The distinction matters because SmartMLS documentation discusses both a sales-to-inventory relationship and a time-to-clear calculation. A figure labeled "absorption" in days or months cannot be compared directly with a monthly percentage.
Report the window and inventory date with the result. A three-month average smooths an unusually busy or quiet month, but it can also conceal a recent change in sales pace. Choose the window before interpreting the number.
Worked example and sensitivity
Every number below is hypothetical. Assume the same local area and property segment, a three-month closed-sales window, and an active-inventory snapshot at the end of that window. These are independent scenarios, not observed market changes.
In the base case, 180 closed sales ÷ 3 months = 60 sales per month. With 300 active homes, 60 ÷ 300 × 100 = 20% monthly absorption. Reversing the inputs gives 300 ÷ 60 = 5 months of supply.
| Scenario | Monthly pace | Active inventory | Monthly absorption | Months of supply |
|---|---|---|---|---|
| Base case | 60 homes | 300 homes | 20% | 5 months |
| Sales slow | 30 homes | 300 homes | 10% | 10 months |
| Inventory falls | 60 homes | 150 homes | 40% | 2.5 months |
When sales slow and inventory stays fixed, the ratio halves and months of supply doubles. When inventory halves but sales do not change, the ratio doubles. That second case does not establish stronger demand: fewer homes are available against the same sales pace.
The five-month result assumes the chosen sales pace continues and no new listings arrive. It is a stock-to-flow comparison, not a schedule for clearing every property. New listings, withdrawals, price changes and financing conditions can change the next reading.
Check the inputs before the conclusion
These are Zero Flux's suggested checks when reading a local report or building your own calculation. Keep the data provider's definition attached to the figure.
Match the segment
Use the same geography, property type and price band for sales and inventory. Citywide sales divided by inventory from one neighborhood produces a misleading ratio.
Match the listing rules
Record whether inventory includes pending homes, new construction, relisted properties or only active resale listings. Changing those rules breaks the comparison even if the calculation is unchanged.
Show the dates
Name the closed-sales window, inventory snapshot and report release date. Sales over three months and inventory at one date are different types of input, not the same group of homes followed through time.
Check seasonality and revisions
Prefer like-for-like local comparisons, including the same season where useful. Keep adjusted and unadjusted inputs separate, and record whether a provider has revised an earlier observation.
Read the components
Show inventory and sales pace beside the final ratio. Add local prices, price reductions and days-on-market evidence before drawing a conclusion about bargaining conditions.
NAR's existing-home sales methodology reports seasonally adjusted annualized sales rates. An annualized rate represents a year at the adjusted monthly pace; it is not that month's actual closed-sales count. Divide an annualized figure by 12 only if you want that adjusted monthly pace, and do not silently mix it with a different local series.
Percentage thresholds often labeled buyer's, seller's or balanced markets are conventions, not a universal law. State the local report's chosen benchmark and compare a consistent series with its own history. The ratio alone does not establish an appropriate asking price or an investment return.
If a report quotes months of supply, verify that its inventory and sales definitions match before converting to a percentage. This guide uses original examples rather than reproducing NAR data.
For a separate view of purchase costs relative to incomes, read the housing affordability index comparison. Affordability and sales absorption measure different constraints; neither replaces property-specific due diligence.
Frequently asked questions
QUICK ANSWERS
Divide closed sales per month by active inventory, then multiply by 100 to express the monthly sales-to-inventory ratio as a percentage. For a longer window, divide total closed sales by the number of months first. Keep geography, property type and listing rules consistent.
They use the same inputs but reverse the division. Monthly absorption percentage is monthly sales divided by inventory, multiplied by 100. Months of supply is inventory divided by monthly sales. With positive, matching inputs, months of supply equals 100 divided by the percentage.
There is no universal cutoff that identifies a good market or a good investment. Compare a consistent local series with its own history and read it alongside prices, price reductions, days on market and financing conditions. A high ratio can reflect low inventory rather than stronger sales.
A monthly sales-to-inventory ratio can exceed 100% when completed sales exceed the inventory snapshot. Sales are a flow over time; active listings are a stock at one date. This does not mean more than 100% of the same starting listings sold.
With positive inventory and zero recorded sales, the absorption percentage is zero, but months of supply has no finite value under the formula. With zero active inventory, the absorption percentage cannot be calculated. Report the limitation rather than assigning a reassuring number.
No. This residential measure compares completed home sales with for-sale inventory. Commercial net absorption measures the change in occupied space or units over a period. The units, data definitions and reader questions differ.
How we reviewed this
Sources reviewed October 12, 2026. This is a methodology guide, not a current market report. Calculations and scenarios are original hypothetical examples. No NAR dataset is reproduced. The input checks and interpretation guidance are Zero Flux's recommendations.