How Actual Cash Value Is Calculated in Home Insurance: Worked Examples

When your roof is damaged and your policy pays **actual cash value**, the insurer isn't writing you a check for a brand-new roof — it's paying what your old, worn roof was worth right before the damage happened. That number is usually arrived at with a formula: replacement cost minus depreciation. Here's how insurers run that math, using a hypothetical worked example.

The basic formula

The **III** (Insurance Information Institute) defines actual cash value, or ACV, as the replacement cost of your damaged property minus depreciation for wear and tear, age, and other factors. In shorthand, and as usually calculated: ACV = replacement cost − depreciation, though this is III's usual formula rather than the only method insurers may use. This is different from **replacement cost value** (RCV): in NAIC's worked example, an RCV policy on the same roof pays the full replacement cost minus the $1,000 deductible, with no depreciation deducted, for a $14,000 payout.

Worked example: depreciating a 10-year-old roof

NAIC's consumer claims guide walks through this exact scenario using two hypothetical households, the Smiths and the Johnsons, both with a roof that originally cost $15,000 and a $1,000 policy deductible. The Johnsons' policy pays ACV and depreciates the roof at $1,000 per year. After 10 years, that's $10,000 in accumulated depreciation. Subtract that $10,000 from the $15,000 replacement cost, then subtract the $1,000 deductible, and the ACV payout comes to $4,000. The Smiths, with an otherwise identical roof but an RCV policy, get $14,000 after the same $1,000 deductible, since RCV doesn't subtract depreciation at all. Same roof, same age, same deductible — a $10,000 difference in payout, entirely driven by how depreciation is treated.

• replacement cost: 15000
• depreciation per year: 1000
• roof age years: 10
• deductible: 1000
• Formula: replacement cost - (depreciation per year * roof age years) - deductible
• Result: 4000

NAIC's Johnson household example: a 10-year-old roof settled on an ACV basis.

It's not just roofs

The same depreciation logic applies to personal belongings, not just structures. NAIC's guide uses a two-year-old laptop that would cost $750 to replace new. Assuming a four-year useful life, the laptop depreciates 25% per year, so at two years old it has lost 50% of its value — putting its actual cash value at $375 at the time it's destroyed. The mechanics are identical to the roof example: figure out replacement cost, apply a depreciation rate tied to expected useful life, and subtract.

Don't forget the deductible can be a percentage

Deductibles aren't always a flat dollar amount. NAIC illustrates a percentage deductible using a $250,000 insured value with a 2% deductible, which works out to $5,000. That $5,000 gets subtracted from the claim payout the same way a flat $1,000 deductible would in the roof example. Percentage deductibles for wind, hurricane, and hail claims are common in some states, so it's worth checking your declarations page to see which type applies before you estimate what an ACV settlement might look like.

• insured value: 250000
• deductible percentage: 0.02
• Formula: insured value * deductible percentage
• Result: 5000

NAIC example: a 2% deductible on a $250,000 insured structure equals $5,000, subtracted the same way a flat-dollar deductible would be.

Key takeaways

• In NAIC's 10-year-old roof example, ACV paid $4,000 versus $14,000 under RCV on the same $15,000 roof and $1,000 deductible
• Because roofs are assumed to last about 25 years, a 20-year-old roof under ACV may be paid at as little as 20% of replacement cost
• The same depreciation math applies to personal property, like a two-year-old $750 laptop valued at $375 under ACV
• Deductibles can be a flat dollar figure or a percentage of insured value — for example, a 2% deductible on a $250,000 insured value works out to $5,000, subtracted from the claim payout the same way a flat deductible would be

ACV versus RCV on the same 10-year-old roof

Detail	ACV policy (Johnsons)	RCV policy (Smiths)
Replacement cost of roof	$15,000	$15,000
Depreciation deducted	$10,000 ($1,000/year over 10 years)	$0 (RCV doesn't deduct depreciation)
Deductible	$1,000	$1,000
Final insurance payment	$4,000	$14,000

Same roof, same $1,000 deductible, and NAIC's illustrative $1,000-per-year depreciation schedule — two different settlement methods on the same $15,000 replacement cost.

Does every insurer depreciate a roof at exactly $1,000 per year?

No — that $1,000-per-year rate comes from one specific NAIC illustration built around a $15,000 roof; actual depreciation schedules vary by insurer, roofing material, and state.

Is ACV always worse for the policyholder than RCV?

In the examples here, yes — the ACV payout was consistently lower than the RCV payout on the same loss, whether it's a $10,000 gap on a roof claim or a lower percentage of replacement cost on an aging roof.

Sources

• www.iii.org
• content.naic.org