Basement Finishing Cost Calculator

Get a realistic estimate to finish your basement. Covers framing, drywall, flooring, electrical, plumbing, and egress windows with an itemised breakdown.

Basement Finish Cost by Level

LevelCost / sq ftTypical total (800 sqft)
Basic$25 – $50$20k – $40k
Mid-Range$50 – $90$40k – $72k
High-End$90 – $150+$72k – $120k+

How Much Does It Cost to Finish a Basement in 2026?

Finishing a basement typically costs $25–$90 per square foot, or $20,000–$75,000 for an average 800 sq ft space. It is one of the best home improvement investments — most homeowners recoup 70–75% of the cost at resale, and it adds significant usable living space.

What drives the cost?

  • Bathroom — adding a full bathroom is the single biggest cost factor at $8,000–$25,000 depending on complexity and finishes.
  • Egress window — required for any bedroom. Costs $2,500–$5,000 including excavation and installation.
  • Electrical — new panel circuits, lighting, and outlets typically run $3,000–$8,000.
  • Ceiling height — low ceilings sometimes require underpinning, adding $10,000–$30,000.