This calculator adds up price ranges that other publishers have already printed. It does not know your house, your soil or your local labor market, so it cannot tell you what a contractor will charge. What it can do is show, item by item, what four published sources say each piece of work typically costs, and how far apart those sources are.
1. Start from a situation (optional)
Each button selects a combination of work that our guides discuss for that situation, so you can price it. It is not a diagnosis. Water causes vary, and a local professional should confirm yours.
2. Your basement
Example values are pre-filled (30 × 33 ft with 8 ft walls). Replace them with your own measurements.
3. Work to include
Tick what you are considering. Quantities fill in from your measurements; drag the slider or type a number to change them.
4. Result
5. Compare with a quote you received
Enter the total from a contractor’s quote for the same work you selected above. This only places it against the published span. It does not judge the contractor.
Whole-project figures, for comparison
If you only want a ballpark for the whole job, these are the totals the sources publish by basement size. They differ a lot: This Old House prices a 1,000 sq ft basement above $12,000, while Fixr lists $3,000 to $10,000 for the same size.
| Basement size | This Old House (Mar 2026) | Fixr (Feb 2026) |
|---|---|---|
| 500 sq ft | $6,260–$7,461 | $1,500–$5,000 |
| 750 sq ft | Not listed | $2,250–$7,500 |
| 1,000 sq ft | $12,447–$14,833 | $3,000–$10,000 |
| 1,250 sq ft | Not listed | $3,750–$12,500 |
| 1,500 sq ft | $18,634–$22,206 | $4,500–$15,000 |
| 2,000 sq ft | $24,817–$29,575 | $6,000–$20,000 |
Fixr gives a national average of $5,000 and an average range of $3,000 to $10,000, with a low end of $1,500 and a high end of $20,000. This Old House gives an average of $13,640 for 1,000 sq ft.
| Approach (This Old House) | Range | Methods it lists |
|---|---|---|
| Interior | $2,000–$6,000 | Drainage, pumps and sealers |
| Exterior | $7,000–$15,000 | Excavation, membranes and regrading |
| Both | $8,000–$18,000 | Complete systems |
What moves the price
- Size and severity. Both Fixr and This Old House tie the total to basement size and to how serious the water problem is.
- Method. Waterproof paint is the cheapest option listed, while full exterior excavation with drains and a membrane is budgeted at about $20,000 or more by This Old House.
- Labor. Both Fixr and This Old House say waterproofing labor averages about $200 per hour.
- Floor type for a sump pit. Four Seasons lists pits in dirt at roughly $500 to $1,500, but $2,800 to $6,200 when the concrete floor has to be cut.
- Extras people forget. Permits ($75 to $500 for excavation per This Old House and Fixr), gutter work, mold remediation and water-damage repair are often not in a waterproofing quote.
Sources
- This Old House: How Much Does Basement Waterproofing Cost? (updated March 4, 2026)
- Fixr: Basement Waterproofing Cost (updated February 6, 2026)
- LawnStarter: How Much Does a French Drain Cost? (updated October 5, 2026)
- Four Seasons Heating, Cooling & Plumbing: Sump Pump Installation Cost (March 16, 2026; a contractor’s own page, so treat it as one data point)
We do not use a source we could not open and check on the date above. Prices are national figures and change; check the source pages for current numbers.