How to use the basement finish cost calculator
- Measure the floor area you actually plan to finish, not the entire footprint if part of it stays storage or mechanical.
- Pick a finish level. Standard is a full finish (framing, insulation, drywall, flooring, basic electrical) from three guides. Basic is shell or half-finished work from two sources. Premium is a mid-range or suite-level finish from two sources.
- Switch on a bathroom if you are adding one. That add-on is a two-source $10,000–$25,000 line (typical $17,500). A crawl space, rather than a basement, is priced on the crawl space encapsulation cost calculator.
Standard $37.50 per sq ft, and why Angi $7–$23 is set aside
HomeGuide (February 6, 2026) prices a finished basement at $30–$50 per sq ft (center $40). Thumbtack (July 10, 2026) says finishing costs $25–$50 per sq ft on average (center $37.50). Fixr (January 30, 2025) puts finishing an unfinished 900 sq ft basement at $15,000–$30,000, about $17–$33 per sq ft (center $25). The median of those three centrals is $37.50 per sq ft, with a spread of $25–$40. On 1,000 sq ft that is typically $37,500, in a $25,000–$40,000 band.
Angi (October 29, 2026) also publishes $7–$23 per sq ft and a $32,000 national average (typical project $15,000–$75,000). Those two Angi figures conflict: $7–$23 on 1,000 sq ft would be $7,000–$23,000, below the $32,000 average. The $32,000 average sits comfortably inside a 1,000 sq ft standard finish, so it is shown as project context and is not blended into the $37.50 typical. The $7–$23 band is treated as shell or half-finished work and, with Block Renovation’s supporting $15–$30 basic range, feeds only the basic tier (two sources). Premium uses HomeGuide’s mid-range $50–$75 sister-article band and Block’s $75–$120 full-suite range — two sources, labeled as such. This Old House and NerdWallet repeat Angi and are not counted again.
A worked example: 1,000 sq ft standard finish
A 1,000 sq ft basement at $37.50 per sq ft typically costs $37,500, with a spread of $25,000–$40,000. Adding a bathroom at the two-source $17,500 typical brings the total to $55,000. Angi’s $32,000 average is a useful project check on this size, and it already falls inside the standard spread.
Sources & assumptions
How this calculator gets its numbers. Full method: our methodology.
- Standard typical $37.50 per sq ft is the median of HomeGuide $30–$50, Thumbtack $25–$50 and Fixr’s implied $17–$33 on a 900 sq ft unfinished basement.
- Angi’s $7–$23 per sq ft conflicts with its $32,000 national average and is used only for the basic / shell-level tier, together with Block Renovation’s $15–$30 basic range (two sources).
- Premium uses HomeGuide’s mid-range $50–$75 sister-article band and Block’s $75–$120 full-suite range (two sources). The bathroom add-on typical $17,500 uses HomeGuide and Block $10,000–$25,000 (two sources); Thumbtack’s $2,500–$5,000 rough-in is not mixed in.
- Angi’s $32,000 average is shown as project context and is not blended into the standard $/sq ft typical. This Old House and NerdWallet repeat Angi and are not counted again.
Sources
- HomeGuide, Cost to Finish a Basement. Feb 6, 2026: $30–$50 per sq ft; bathroom addition $10,000–$25,000.
- HomeGuide, How Much Value Does a Finished Basement Add? Sister article: basic $30–$50, mid-range $50–$75, high-end $75–$150+ per sq ft.
- Angi, How Much Does It Cost to Finish a Basement? Oct 29, 2026: $7–$23 per sq ft (shell / half-finished); national average $32,000; typical $15,000–$75,000.
- Thumbtack, Basement Remodel Cost. Jul 10, 2026: finishing a basement costs $25–$50 per sq ft on average.
- Fixr, Basement Remodeling Cost. Jan 30, 2025: finishing an unfinished 900 sq ft basement $15,000–$30,000 (about $17–$33 per sq ft).
- Block Renovation, The Complete Guide to Basement Remodel Costs. Sep 30, 2026: basic $15–$30, standard $30–$75, full living suite $75–$120+ per sq ft; bathroom $10,000–$25,000. Supporting contractor marketplace.
Last reviewed . Installed prices vary by region, contractor and job conditions; a written local bid wins.
Frequently asked questions
How much does it cost to finish a 1,000 sq ft basement?
A standard finish typically costs $37,500, from the $37.50 per sq ft median of HomeGuide, Thumbtack and Fixr. The spread of those central values is $25–$40 per sq ft, or $25,000–$40,000 on this size.
Why don’t you average in Angi $7–$23 per sq ft?
That band conflicts with Angi’s own $32,000 national average, which already sits inside a 1,000 sq ft standard finish. The $7–$23 figure is used only for the basic / shell-level tier, together with Block Renovation’s $15–$30 basic range.
How much is a basement bathroom?
HomeGuide and Block Renovation both list $10,000–$25,000 to add a bathroom, so the two-source typical is $17,500. Thumbtack’s $2,500–$5,000 figure is for a roughed-in bath and is not mixed into that add-on.
Is a crawl space the same job?
No. Encapsulating a crawl space is a different scope and is priced on the crawl space encapsulation cost calculator.