Basement Calculator

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Basement Finishing Cost Calculator

Enter the area, pick a finish level and your state, and add the bathroom and windows you need.

sq ft
Finish level
Adjusts the labor share using BLS May 2025 trade wages.
Cutting the foundation, the well and the window.
windows

Your result

Enter your numbers and press the button.

Basement finishing cost by size

SizeBasicMid-rangeHigh-end
400 sq ft$10,000–$16,000$16,000–$30,000$30,000–$40,000
500 sq ft$12,500–$20,000$20,000–$37,500$37,500–$50,000
600 sq ft$15,000–$24,000$24,000–$45,000$45,000–$60,000
700 sq ft$17,500–$28,000$28,000–$52,500$52,500–$70,000
800 sq ft$20,000–$32,000$32,000–$60,000$60,000–$80,000
900 sq ft$22,500–$36,000$36,000–$67,500$67,500–$90,000
1,000 sq ft$25,000–$40,000$40,000–$75,000$75,000–$100,000
1,100 sq ft$27,500–$44,000$44,000–$82,500$82,500–$110,000
1,200 sq ft$30,000–$48,000$48,000–$90,000$90,000–$120,000
1,300 sq ft$32,500–$52,000$52,000–$97,500$97,500–$130,000
1,400 sq ft$35,000–$56,000$56,000–$105,000$105,000–$140,000
1,500 sq ft$37,500–$60,000$60,000–$112,500$112,500–$150,000
1,600 sq ft$40,000–$64,000$64,000–$120,000$120,000–$160,000
1,800 sq ft$45,000–$72,000$72,000–$135,000$135,000–$180,000
2,000 sq ft$50,000–$80,000$80,000–$150,000$150,000–$200,000

Block Renovation 2026 contractor-led ranges: $25–$40, $40–$75 and $75–$100 per sq ft.

How this estimate is built

The base number is area times a published cost per square foot. Block Renovation, a remodeling contractor, puts contractor-led basement finishes at $25–$40 per square foot for a basic finish, $40–$75 for mid-range and $75–$100 or more for high-end work in 2026. HomeAdvisor's national figure is lower, $7–$23 per square foot, because it also counts partly finished spaces and owner-managed projects. Use the HomeAdvisor range if you will act as your own general contractor or only need flooring, paint and lighting in an already dry, framed room.

Add-ons are priced separately because they do not scale with area. A bathroom costs about the same whether it sits in a 600 or a 1,600 square foot basement. Fixr lists half baths at $5,000–$15,000, three-quarter baths at $10,000–$22,000 and full baths at $15,000–$35,000. HomeGuide puts a cut-in egress window at $4,000–$12,000, most often $6,000–$8,000. HomeAdvisor lists permits at $1,200–$2,000.

When you pick a state, the calculator keeps 60% of the cost as is and scales the other 40% by local wages. This Old House notes that labor is usually about 40% of a basement finishing budget, and the wage index comes from the Bureau of Labor Statistics' May 2025 mean hourly wages for carpenters, electricians, plumbers and drywall installers.

Add-ons

Add-onLowHigh
Half bath$5,000$15,000
Three-quarter bath$10,000$22,000
Full bath$15,000$35,000
Egress window, each$4,000$12,000
Building permit$1,200$2,000

Bathroom ranges from Fixr; egress from HomeGuide; permits from HomeAdvisor.

What moves the price

  • Water. A basement that leaks must be fixed first. HomeAdvisor's average waterproofing job is $4,400, and none of that shows up in a per-square-foot finishing price.
  • Plumbing. Adding a toilet below the sewer line needs an ejector pit or upflush system. Rough-in pipes left by the builder cut the cost of a bathroom sharply.
  • Ceiling height. Ducts and beams that hang below 6′ 4″ have to be moved, or the floor lowered, before a room can count as habitable.
  • Bedrooms. Every sleeping room in a basement needs its own emergency escape opening under IRC R310, so each bedroom can add an egress window.
  • Finish choices. Block Renovation lists luxury vinyl plank at $3–$7 per sq ft installed, carpet at $2–$5 and ceramic tile at $5–$10.

Getting comparable bids

  1. Write a one-page scope: rooms, bathroom fixtures, number of egress windows, ceiling type and flooring.
  2. Ask each contractor to price the permit, the water fix and any electrical panel work as separate lines.
  3. Ask whether quotes include design, dumpster and final cleaning.
  4. Compare per-square-foot totals only after removing the bathroom and egress lines, which do not scale with area.
  5. Check the license, insurance and recent permits of each contractor with your building department.

The usual order of work

PhaseWhoNotes
1. Water and radonWaterproofer, mitigatorTest radon and fix leaks before anything is covered
2. Permit and planOwner, designerRooms, egress windows, bathroom location
3. Egress and drainsExcavator, plumberCut windows and break slab for drains while the space is open
4. Framing and insulationCarpenterFoam on the concrete, treated bottom plates, fire blocking
5. Rough electrical, plumbing, HVACLicensed tradesInspections before walls close
6. Drywall and ceilingDrywall crewLeave access panels for valves and cleanouts
7. Flooring, trim, paint, fixturesFinish trades or ownerFinal inspection

Bathroom and egress costs land early, in phase 3, which is why they surprise people who budget only by the square foot.

Cost calculators

Common questions

What is the average cost to finish a basement?

HomeAdvisor reports a typical range of $15,000–$75,000 and an average of $32,000. Contractor-led work runs $25–$75 per square foot in most 2026 projects according to Block Renovation.

Does a bathroom double the cost?

Not usually. A full bath adds $15,000–$35,000. On a 1,000 sq ft mid-range finish ($40,000–$75,000) that is a large share but well short of double.

Why do online estimates disagree so much?

Some figures include only finishing touches on spaces that are already framed and wired, and some include owner-managed projects. Contractor-led finishes from bare concrete cost more.

Related calculators

Sources

  • https://www.blockrenovation.com/guides/basement-remodel-cost-per-square-foot-2026
  • https://www.homeadvisor.com/cost/basements/
  • https://www.thisoldhouse.com/foundations/reviews/cost-to-finish-basement
  • https://www.fixr.com/costs/bathroom-addition
  • https://homeguide.com/costs/egress-window-installation-cost
  • https://api.bls.gov/publicAPI/v1/timeseries/data/ (OEWS series OEUS…472031, 472111, 472152, 472081, May 2025)