Zoopla has defended its pricing tool after it was revealed that asking prices in many areas of the country were as much as 20% above the portal’s estimated average valuation.

Last week the Coventry Telegraph said that the average asking price in the midlands city was currently £210,000, while Zoopla’s pricing tool put the average property price in the area at £173,000.

A spokesman for Zoopla explained: “Zoopla valuation estimates are our assessment of the market value at any given time, calculated using a proprietary algorithm that continuously analyses millions of data points relating to property sales and home characteristics.

“It is misleading to compare average asking prices to our estimate of average property values in a given area since only a small fraction of homes in any area, typically less than 5%, are on the market at any given time.

“Therefore average asking prices can easily be skewed, whereas our estimated average values takes into consideration all homes in the area.”

In Birmingham, asking prices were 19% higher than the average values, while in Smethwick they were 18% higher.

The trend continued in London. In Kensington the current average asking price is £2.379m while the Zoopla average value stands at £2.158m.

In Glasgow the average asking price is now £148,000, while Zoopla’s average value is £164,000.