Changing a double sink to a single sink typically costs $450-$2,500, with many standard bathroom projects landing near $1,200. The final price depends mainly on whether the countertop needs replacement or modification, how much drain and water-line work is required, and whether the old sink, faucet, or cabinet must be removed or changed.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Basic conversion | $450 | $1,200 | $2,500 | One sink, existing counter reused, ordinary plumbing access |
| Plumbing labor | $200 | $450 | $900 | Usually $75-$150 per hour, depending on location and scope |
| Countertop change | $150 | $600 | $1,800 | Patch or cutout work costs less than a full replacement |
| Sink and faucet | $150 | $500 | $1,300 | Basic fixtures versus higher-priced materials and finishes |
| Removal and disposal | $50 | $200 | $500 | Higher if a large vanity or heavy top must be hauled away |
Assumptions: Typical U.S. bathroom, standard-quality fixtures, accessible plumbing, and no major cabinet or wall repairs.
What Does It Cost to Replace a Double Sink With One?
A straightforward conversion generally costs $450-$1,200 when the existing vanity and countertop can stay, one basin fits the available opening, and the second drain and faucet connections can be capped or removed without moving the main plumbing. That estimate typically covers a plumber, a basic sink, supply-line adjustments, drain fittings, and testing.
Projects that require countertop alteration, a new faucet, or more extensive plumbing usually run $1,200-$2,500. A full vanity and counter replacement, premium stone, cabinet changes, or wall repairs can push the total to $3,000-$5,000 or more. These higher totals reflect a broader bathroom update, not simply swapping two basins for one.
For a single-basin installation, labor and parts commonly work out to about $450-$1,500 per sink conversion, excluding a full vanity replacement. The price varies by basin type and whether it is drop-in, undermount, or vessel-style. A top that already has a suitable single-sink opening can keep the project near the low end; an incompatible double cutout can make a new counter the most expensive item.
The cheapest result usually comes from keeping the vanity and counter while making only the plumbing changes required to serve one basin.
How Countertop, Plumbing, and Labor Shape the Quote
Written estimates may group materials and labor together, so asking for itemized charges helps show whether the job includes countertop work, fixture installation, drain closure, and disposal. The ranges below are typical planning figures; a contractor may combine tasks into one minimum service charge.
| Quote item | Typical price | What it covers | When it increases |
|---|---|---|---|
| Plumbing labor | $200-$700 | Disconnecting the second basin and adapting the drain and supplies | Pipe relocation, access problems, or old corroded fittings |
| Sink and faucet materials | $150-$900 | One basin, faucet, drain assembly, and basic connectors | Stone, fireclay, designer faucet, or specialty finish |
| Countertop work | $150-$1,800 | Cutout adjustment, patching, or replacement top | Large opening, brittle material, or custom fabrication |
| Cabinet adjustment | $100-$700 | Interior shelf or divider changes and minor finish repair | Structural modifications or replacement doors and panels |
| Removal and disposal | $50-$500 | Hauling away an old sink, counter, or vanity | Heavy stone, stairs, limited parking, or bulky debris |
Plumbing labor commonly runs $75-$150 per hour, and a plumber may charge a $100-$250 minimum for a small service call. A simple conversion can take 2-4 hours of plumbing work, while a job involving counter fabrication or cabinet repair may require separate trades and additional visits.
Countertop work is often the largest uncertainty because an unusable second cutout may require more than a simple plumbing cap.
What Local Labor Rates Add in U.S. Markets
Local labor rates and material availability can shift a comparable quote by roughly 10%-30%. Major metropolitan areas and high-cost coastal markets often fall toward the upper end, while smaller cities and rural areas may have lower hourly rates but fewer nearby countertop fabricators. Travel fees or a contractor’s minimum charge can reduce that apparent savings on a short job.
For planning, a basic conversion might cost $450-$1,000 in a lower-cost market, $800-$1,700 in a typical mid-priced market, and $1,200-$2,500 in an expensive urban area when the top can be reused. These are broad estimates, not fixed regional price lists. The same project can cost more if the bathroom is difficult to access or a specialist must make a custom countertop piece.
Stone and solid-surface work can also be regionally sensitive because fabricators price cutting, polishing, and installation according to material, shop capacity, and travel. Ask whether the quote includes measurement, fabrication, delivery, and installation. A low fabrication number may not include those separate charges.
Comparing itemized quotes from local plumbers and countertop installers is more useful than applying a single national multiplier.
Which Drain and Countertop Changes Raise the Price?
The number and position of existing drain lines matter. If both sink drains meet in an accessible common branch beneath the vanity, a plumber can often remove one trap and close or reconfigure the unused connection with relatively little work. If a drain must move more than 12-24 inches, or the wall must be opened to reach it, labor and patching can add $250-$900 or more.
Countertop layout is another major driver. A single-sink top with an opening that matches the new basin may need only minor fitting. A double-sink top with two separate openings may be difficult to patch invisibly, particularly in granite, quartz, or porcelain. Replacing a vanity top can add $500-$1,800 for common prefabricated options; custom stone and a larger vanity can exceed $2,500 installed.
Sink size and mounting style also affect the estimate. A basin that fits within the existing cabinet and cutout dimensions avoids cabinet carpentry. A change from undermount to drop-in, or from two smaller bowls to one wide bowl, may require a different opening and edge treatment. A 30-36-inch single-basin vanity top often has more standard replacement options than a custom-width top.
Water supply lines are usually inexpensive to adapt when shutoff valves are sound, but seized valves or leaking connections can add $100-$400. Plumbing codes and local inspection requirements vary; moving lines or opening a wall may trigger requirements that a like-for-like fixture change does not.
Confirm the drain location, sink dimensions, mounting style, and countertop material before accepting a fixed-price quote.
Can One Sink Fit the Existing Vanity and Cutout?
Sometimes the existing counter can be reused, but the answer depends on its openings, not simply on the available cabinet width. If one bowl is removed and the remaining basin opening already suits the selected sink, the unused faucet holes and second cutout still need a practical finish. A vanity top with an integrated basin may not allow a clean repair at all.
Possible options include replacing the entire top, installing a compatible replacement section, or choosing a sink-and-countertop assembly designed to cover the old openings. A small patch may work with laminate or a top that has a matching material and finish. Quartz and natural stone generally need a fabricator, and even a technically sound patch may remain visible.
Cabinet width alone is not enough to confirm fit. Check the distance from the vanity sides to the drain, the depth of the sink bowl, faucet clearance, and the cabinet interior. A large single basin can conflict with a drawer, center divider, or plumbing that was arranged for two separate bowls. Adjusting a nonstructural shelf may cost $100-$300; altering the cabinet box or replacing doors costs more.
Have the installer verify the cutout and cabinet measurements before ordering a sink or countertop.
When Removal, Faucet, or Cabinet Work Adds Charges
Removing the second sink may involve more than disconnecting pipes. A glued or caulked basin can damage the surrounding counter during removal, while a heavy stone top may need two or more workers. Sink removal and disposal often add $50-$200; removing a full vanity and counter can cost $150-$500, depending on weight, access, and local disposal fees.
A new faucet can add $75-$350 for a standard model or $350-$800 or more for a premium fixture. The faucet may be reused if its finish is sound and its hole configuration matches the new sink. Replacing old shutoff valves, flexible supply lines, or a worn P-trap can add $25-$250 in parts and labor, with higher charges if the fittings are stuck or leaking.
Cabinet and wall repairs are usually outside a basic plumbing quote. Removing a double vanity can reveal unpainted wall areas, damaged flooring, or holes left by plumbing. Small touch-up work may cost $100-$300, while repainting a larger area, replacing flooring, or installing a new cabinet can add several hundred dollars or more.
Clarify whether the bid includes haul-away, patching, faucet installation, and replacement of aging shutoff valves.
Three Single-Sink Conversion Quotes for Common Bathrooms
The examples below show how scope changes the total. They assume ordinary access and standard labor; local rates, fixture choices, and actual countertop measurements can change the bid. Each total includes typical labor and listed work rather than a full bathroom remodel.
| Example | Scope and unit pricing | Estimated total |
|---|---|---|
| Reuse a compatible top | Sink $120-$250; faucet and drain $100-$220; plumber 3 hours at $90-$130 per hour; minor supplies $40-$100 | $530-$960 |
| Replace a 48-inch vanity top | Top $450-$900; sink and faucet $200-$450; plumbing 4-6 hours at $100-$145 per hour; removal $100-$250 | $1,150-$2,470 |
| Custom stone and drain relocation | Fabricated top $1,000-$2,200; fixtures $300-$700; plumbing 6-9 hours at $110-$160 per hour; disposal and patching $250-$700 | $2,210-$5,040 |
In the first example, the existing vanity remains in place and the counter already accepts the selected sink. The second assumes a standard prefabricated top and ordinary removal. The third reflects custom fabrication and a drain move; it may also require separate countertop and plumbing appointments.
Use these totals as quote-comparison benchmarks, not guaranteed prices for a specific bathroom.
Where Can Homeowners Cut the Conversion Budget?
Keeping the vanity, countertop, and faucet is usually the most effective way to reduce the bill, provided each item is sound and compatible with the new layout. Choosing a sink that fits an existing opening can avoid fabrication charges. If a new top is needed, compare standard-size vanity tops with custom stone; a prefabricated option may save several hundred dollars while still including a basin.
Ask for separate prices for plumbing, counter work, fixtures, and disposal. This makes it easier to identify optional upgrades and compare quotes on the same scope. Confirm whether the contractor has included repair of the unused basin opening. A quote that omits this step may look inexpensive but leave an unfinished counter or an unusable second cutout.
Replacing an entire vanity is not automatically necessary. If the cabinet is sturdy, dry, and correctly sized, a top replacement may be enough. Conversely, if water damage or broken cabinet supports are present, paying for plumbing and a new counter on top of a failing base can lead to repeat costs. Have visible damage assessed before ordering materials.
Homeowners can clear the vanity, remove stored items, and provide a clear route to the bathroom before the crew arrives. They should not disconnect plumbing or remove a stone top unless qualified to do so. Scheduling during a contractor’s less-busy period may improve availability, but rush work or short-notice scheduling can add $100-$300 or more.
Control the scope first, then compare complete written estimates that include the same sink, counter, plumbing, and disposal work.