Door material compare: steel, fiberglass & wood
Compare steel, fiberglass and wood exterior doors on a level footing — cost per year of service life, from your prices.
On a cost-per-year basis from YOUR prices, steel is $40.00/yr, fiberglass $50.00/yr and wood $66.67/yr. Steel is the value/security default, fiberglass resists dents and weather with low upkeep, wood looks best but needs finishing — a labeled compare, not a verdict.
Calculator inputs
A cheaper door is not always the better buy. An exterior door that lasts longer for a higher upfront price can cost less per year of service than a bargain door you replace sooner. This tool puts steel, fiberglass and wood on the same footing by dividing each door’s cost by its service life — a plain, honest comparison lens built from your prices, not a verdict.
The three materials trade off differently: steel is the value and security default, fiberglass resists dents and weather with low upkeep, and wood looks best but needs periodic finishing to reach its potential life. Enter what each costs you and how long you expect it to last.
Formula
For each material, total the doors and divide by the service life:
cost = count × price/doorcost per year = cost ÷ service life (years)
Prices are yours; the lifespans are LABELED planning typicals you can override with your own expectation for the product and your exposure.
Worked example
One door of each, at their default prices and lifespans:
- Steel —
1 × 800 ÷ 20 = $40.00 / yr - Fiberglass —
1 × 1,500 ÷ 30 = $50.00 / yr - Wood —
1 × 2,000 ÷ 30 = $66.67 / yr
On these numbers steel is the lowest cost per year and wood the highest — but the gap narrows if you expect the fiberglass or wood door to outlast the estimate, which is exactly why the lifespans are yours to change.
What each material is good at
- Steel — the value and security default: strong, affordable and low-maintenance, but it can dent and, once the finish is breached, can rust; insulated cores give decent efficiency.
- Fiberglass — dent- and weather-resistant with very low upkeep, holds a wood-grain finish well and typically lasts longest for the money; a strong all-round exterior choice.
- Wood — the best looks and feel and easily repaired, but it needs periodic sealing or painting and can swell, warp or rot if the finish lapses, especially on a sun- or weather-exposed opening.
Cost-per-year is a comparison lens, not a durability guarantee: exposure, finish quality and maintenance move real service life more than the material label. Match the material to the opening — a covered entry forgives wood, a sun-baked west door rewards fiberglass.
Reference table
| Material | Typical service life | Character |
|---|---|---|
| Steel | 15–30 years | Value / security default |
| Fiberglass | 30–50 years | Dent- and weather-resistant, low upkeep |
| Wood | 20–40 years | Best looks; needs finishing |
Lifespans are LABELED planning typicals; real service life depends on exposure, finish and maintenance. Cost-per-year is a comparison lens, not a durability guarantee.