CodeKitHubWhat Is This Tool?
The comparable method (also called the comparable sales method) is the standard approach used by RICS-qualified surveyors to estimate land value when direct market transactions exist for similar plots. It works by taking sales of comparable land parcels — similar size, location, planning status — and adjusting the resulting price per unit area for differences in plot size, location and scarcity.
For agricultural land and larger building plots, UK valuers typically express the comparable price per acre; for garden land and smaller residential plots, price per square metre or square foot is more common, since garden land often sells at a significant premium to bare agricultural land, especially to an adjoining owner who wants to extend a garden or build a self-build home.
This tool asks you to enter your own comparable price per square metre, sourced from recent local sales, an estate agent, or a surveyor's guidance — it does not supply or guess a market price on your behalf, since land prices vary enormously even within the same postcode.
Why Use It?
- You're thinking about selling off the bottom third of your garden to a neighbour who wants to extend theirs, and before calling an agent you want a rough sanity-check figure based on what similar strips of garden land have actually sold for nearby.
- You've spotted a Land Registry Price Paid entry for a comparable plot down the road and want to apply that same £/m² figure to your own plot's exact area instead of doing the multiplication by hand or guessing.
- You're weighing whether to apply for outline planning permission on a paddock before selling it, and want to see roughly how the same area values out at an agricultural price per acre versus a residential price per square metre, to judge if pursuing planning is worth the cost and delay.
- You're dividing an inherited property between siblings and need a defensible starting figure for what the land portion (separate from the house) might be worth, before a formal RICS valuation for probate.
- You want to sanity-check a number an estate agent or a prospective buyer has quoted you, by plugging in the same area and a comparable price you've sourced independently and seeing if the figures roughly agree.
- Free, instant, no sign-up — the calculation runs entirely in your browser.
How to Use
- Enter the land area you want to value.
- Choose whether that area is in square metres or acres.
- Enter your comparable price per square metre, based on recent sales of similar nearby plots or a surveyor's estimate.
- Review the estimated land value, along with the area converted to both square metres and acres.
Example
Input
500 m² garden plot, comparable price £150 per m²Output
Estimated land value: 500 m² × £150/m² = £75,000This reflects only the area-times-price calculation. A real garden plot's sale price can differ substantially depending on whether it has separate development potential (e.g. outline planning permission for a self-build), whether it's being sold to an adjoining neighbour who values it more highly for extending their own garden, and local planning policy — factors this simple calculation cannot capture.
Garden plot vs. agricultural land vs. building plot pricing
| Land type | Typical pricing unit | Key value driver |
|---|---|---|
| Garden plot (no separate planning) | £ per m² | Value to an adjoining owner or as part of the main property |
| Garden plot with self-build/outline planning potential | £ per m² | Whether planning permission is likely to be granted |
| Agricultural land | £ per acre | Soil quality, access, and any hope value for future development |
| Building plot with full planning permission | £ per m² or per unit | Number and type of units the permission allows |
Where to find a comparable price
- Land Registry Price Paid Data for recent sales of similar plots in your area
- Local estate agents who specialise in land and plot sales
- A RICS-qualified surveyor's professional valuation
- Specialist land-marketing sites that list current asking prices for comparable plots nearby
Important note
This calculator gives a simplified, indicative estimate based on the comparable price you supply — it is not a formal valuation and does not account for planning status, access rights, ground conditions, or the specific buyer demand that can significantly move a real sale price. For a garden land sale, subdivision, inheritance tax, or any transaction that matters financially, get a valuation from a RICS-qualified surveyor and check current planning policy with your local council before relying on this figure.
Why hope value can make land worth more than a calculation like this suggests
"Hope value" is a term UK valuers use for the portion of a plot's price that reflects the possibility of getting planning permission in the future, even if that permission doesn't exist yet — and it's the single biggest reason a straightforward area-times-price calculation can undersell what land is actually worth.
A field with no planning history might sell for a modest agricultural price per acre on its own, but the same field next to a growing village boundary, with informal indications from planning officers that residential development might eventually be supported, can command a substantial premium over bare agricultural value — buyers are willing to pay extra now for the chance of a much larger payoff later if planning comes through. This calculator has no way to price in that possibility, since it depends entirely on local planning policy, five-year housing land supply figures, and judgment calls that only a planning consultant or specialist valuer can properly assess. If your land sits anywhere near a settlement boundary or a site allocated for future development in your council's Local Plan, a plain comparable-price figure from this tool is likely to understate its true value, and it's worth getting specific planning advice before selling or valuing it for any formal purpose.
Frequently Asked Questions
Is there an official UK government land value calculator?
No. Unlike house price indices, there is no single official calculator that returns a precise land value in the UK, because land value depends heavily on planning permission status, location and individual buyer demand. Professional valuers use the comparable method as a starting point but combine it with local market knowledge, planning research and, for larger sites, a residual valuation that accounts for development costs.
How much is my garden land worth?
Garden land value depends on whether it has separate development potential and who the likely buyer is. Land sold to a developer or as a self-build plot with planning permission typically commands a much higher price per square metre than the same land valued as part of a house's garden. Land sold to an adjoining neighbour who wants to extend their own garden also often achieves a premium, since it's worth more to them than to the open market. A local estate agent or RICS surveyor can give a realistic figure for your specific situation.
Should I use price per square metre or price per acre?
For garden plots and small residential land parcels, price per square metre is the more common and precise unit in the UK. For agricultural land or larger building sites, price per acre is standard. This calculator lets you enter area in either unit and converts automatically (1 acre = 4,046.86 m²), but it always uses your comparable price per square metre for the calculation.
Does this account for planning permission?
No. This calculator only multiplies area by a comparable price you provide — it does not automatically factor in whether the land has, or could get, planning permission. Planning status is often the single biggest driver of land value in the UK, so if your plot has or could obtain permission, your comparable price should reflect sales of similarly-permissioned land, not bare agricultural land.
Is my data stored anywhere?
No. All calculations run using JavaScript in your own browser; the area and price you enter are never sent to a server or stored anywhere.
Where do I actually find a comparable price per square metre to enter?
The most reliable free source is HM Land Registry's Price Paid Data, which lists actual sale prices for registered transactions — though it records the total price paid, not always a per-m² breakdown for land-only sales, so you may need to divide the sale price by the plot's area yourself once you find a genuinely comparable transaction. Local estate agents who handle land and plot sales, and land-specific listing sites showing current asking prices nearby, are the other two common sources.
Why does the same size garden plot sell for wildly different prices depending on the buyer?
Garden land is unusual in that its value depends heavily on who's buying it rather than just its size and location. An adjoining neighbour who wants to extend their own garden will often pay a premium above the land's open-market value, since it's worth more specifically to them than to a random buyer. A developer or self-builder, on the other hand, is really paying for the land's development potential, not the grass itself — which is why the exact same plot can be worth several times more with planning permission attached than without it.
My plot is measured in a mix of metres and feet on old title deeds — how do I convert it?
This calculator accepts square metres or acres directly, so if your title deed uses feet, convert to square metres first (1 square foot = 0.0929 m²) before entering the area, or convert your comparable price to a price-per-square-foot basis instead and do the multiplication outside the tool — mixing units between the area and the comparable price will produce a meaningless result.
What's a realistic price per square metre for garden land in the UK right now?
There is no single figure — garden land prices vary enormously by region and even street to street, from under £50/m² for bare land with no development prospects in low-demand areas to several hundred pounds per m² for garden land in high-value areas with self-build potential. This is exactly why the calculator asks you to supply your own comparable price rather than guessing a national average, which would be meaningless for any specific plot.
Does this calculator work for agricultural land, or only garden plots?
Yes — it works for both, since the underlying calculation (area times comparable price) is the same regardless of land type. Just make sure your comparable price reflects the correct land type: agricultural land comparables (typically priced per acre) shouldn't be applied to a small residential garden plot, and vice versa, since the two markets price very differently.