Calculate finish nails for a trim installation.
Shopping list
Estimated cost
Usage Tip
Drive one nail near each edge of wide trim so it cannot cup; set and fill the heads before painting.
nails = points × nails per point
The result rounds up to whole points.
How many finish nails do I need?
Count the linear feet of trim, decide how often a nail goes in, and multiply by the number of rows. Baseboard and crown usually take two rows of nails every 16 in to catch the framing top and bottom; shoe molding takes a single row. Add a little waste for misfires and you have a box count to take to the store. This calculator does that, then recommends the right gauge and length for the job and totals the cost.
Finish nail gauge guide
Gauge is the thickness of the nail: the lower the number, the thicker and stronger the nail, and the bigger the hole it leaves.
| Gauge | Best for | Holding power |
|---|---|---|
| 15 gauge | Thick or heavy trim, door casing, stair parts, hardwood | Strongest; angled magazine reaches corners |
| 16 gauge | The all-rounder: baseboard, crown, casing, chair rail | Strong, versatile |
| 18 gauge brad | Light trim, shoe molding, returns, MDF, small casing | Light; tiny hole |
| 23 gauge pin | Delicate moldings, holding parts while glue dries | Almost none; pairs with adhesive |
Finish nail length guide
A finish nail should pass through the trim and at least 3/4 in into solid framing. A good rule is the trim thickness plus about 1-1/4 in, allowing for drywall in the way.
| Trim thickness | Recommended length |
|---|---|
| 1/2 in | 1-1/2 in |
| 5/8 in | 2 in |
| 3/4 in | 2 to 2-1/2 in |
| 1 in or built-up | 2-1/2 in |
Nail spacing and trim guide
Trim is nailed into framing, so spacing follows the studs. Drive nails at the stud locations and add a few between to keep the trim tight to the wall.
| Trim | Spacing | Rows |
|---|---|---|
| Baseboard | 16 in | 2 (top and bottom) |
| Crown molding | 16 in | 2 (wall and ceiling) |
| Door / window casing | 16 in | 2 (jamb and framing) |
| Chair rail | 16 in | 1 to 2 |
| Shoe / quarter-round | 12 in | 1 |
| Wainscoting | 12 in | 2 |
Trim examples
Baseboard
A 12 by 12 ft room has about 48 ft of baseboard. At a nail every 16 in in two rows that is roughly 74 nails, plus waste — well under one box. Use 16 gauge, 2 in.
Crown molding
Crown is nailed into the top plate and into the ceiling framing, two rows at 16 in. A 2-1/2 in 15 or 16 gauge nail reaches through the thick profile into solid wood.
Door casing
A standard door takes about 17 ft of casing. Two rows pin the casing to the jamb and to the framing behind the drywall; 16 gauge, 2 in is typical.
Glue, adhesive and the nailer
Nails position and clamp the trim; construction adhesive or glue adds long-term hold, which matters on crown and on long unsupported runs. In glue-plus-nail work the nails mainly hold the piece while the adhesive cures, so a lighter gauge is fine. One tube of construction adhesive covers roughly 25 to 30 linear feet. Most finish work runs off an 18 or 16 gauge nailer and a small compressor, or a cordless equivalent.
Frequently asked questions
How far apart should finish nails be?
About every 16 in to land on studs, with extras between to pull the trim tight. Shoe molding can go to 12 in in a single row.
What gauge nail for baseboard?
16 gauge is the standard for baseboard and most trim. Use 15 gauge for thick or hardwood baseboard, 18 gauge brads for thin or delicate pieces.
How long should finish nails be?
Trim thickness plus about 1-1/4 in, so the nail bites at least 3/4 in into framing. For 5/8 in trim that is about a 2 in nail.
Do I need glue as well as nails?
Not always, but adhesive greatly improves hold on crown and long runs. With glue you can use a lighter gauge since the nails just hold until it cures.
What is a 23 gauge pin nail for?
Headless pins hold small, delicate moldings in place while glue dries. They leave almost no hole but have very little holding power on their own.
How many nails are in a box?
Commonly 1,000 to 2,500 for 15 and 16 gauge, and up to several thousand for 18 gauge brads. Check the box and enter the count to get an accurate box estimate.
Linear Foot Calculator · Project Cost Calculator · Material Estimator · Trim Molding Calculator
Estimates are for planning. Nail spacing, gauge and length depend on your trim profile, framing and local practice; confirm penetration into solid framing and follow your nailer and fastener manufacturer guidance.