There's no clean formula. How land gets assessed varies by state and even by the individual assessor. In the counties we work in most, Orange and LA among them, the assessment process appears to be largely automated. Nobody is carefully weighing lot size or whether a home backs to a busy street. So the intuitive expectation, that an identical house on a bigger lot carries a proportionally higher assessed land value, often fails to show up in the numbers. We've seen this firsthand. With a partner, we once bought two similar, run-down 1950s homes near each other, used one as a direct comp to argue the other's assessed value down, and the county still assessed it above what we had actually paid, even after seeing the comparable sale. The practical takeaway: assessed value is a tax figure. Don't lean on it to judge what a lot is truly worth in a sale. Market value gets settled by buyers, appraisers, and comps, and the assessor's number can sit a long way from all three.