How many drop ceiling tiles?
Type the room's length and width and pick the grid. The drop ceiling calculator counts the ceiling panels, main tees, cross tees and wall angle you need.
- Ceiling panels
- 70
Ceiling panels: 70; main tees: 6; 4 ft cross tees: 36; 2 ft cross tees: 30; wall angle pieces: 6.
- Main tees
- 6
- 4 ft (1200 mm) cross tees
- 36
- 2 ft (600 mm) cross tees
- 30
- Wall angle pieces
- 6
- Ceiling area (ft²)
- 280
- Ceiling area (m²)
- 26.01
Ceiling panels: 70. Ceiling panels: 70; main tees: 6; 4 ft cross tees: 36; 2 ft cross tees: 30; wall angle pieces: 6.
How to calculate
Counts the ceiling panels, main tees, cross tees and wall angle for a rectangular drop ceiling on a 2 × 2 or 2 × 4 grid, with the ceiling area.
Example with the default inputs (Room length 20 ft, Room width 14 ft, Grid 2 × 2 ft, Main tee and wall angle length 12 ft): Ceiling panels: 70; main tees: 6; 4 ft cross tees: 36; 2 ft cross tees: 30; wall angle pieces: 6.
Method: With module m = 2 ft (0.6 m): columns = ⌈L ÷ m⌉, cells = ⌈W ÷ 2m⌉, halves = ⌈W ÷ m⌉; panels = columns × halves (2 × 2) or columns × cells (2 × 4); main tees = (cells − 1) × ⌈L ÷ piece⌉; 4 ft cross tees = (columns − 1) × cells; 2 ft cross tees = columns × (halves − cells) (2 × 2 only); wall angle = ⌈2(L + W) ÷ piece⌉.
- The room is a rectangle. Main tees run along its length 4 ft (1.2 m) apart, starting from one wall; cross tees run across every 2 ft (0.6 m).
- Each cut border panel counts as a whole panel; balancing the borders (equal cuts on both sides) can add a row.
- Hanger wire, screws and spare panels are not counted.
Worked examples
Each example is checked against the calculator on every build.
- Room length 20 ft, Room width 14 ft, Grid 2 × 2 ft, Main tee and wall angle length 12 ft gives Ceiling panels 70, Main tees 6, 4 ft (1200 mm) cross tees 36, 2 ft (600 mm) cross tees 30, Wall angle pieces 6, Ceiling area (ft²) 280.Source: Kanopi by Armstrong, How To Install Drop Ceilings: main beams typically installed 4 ft on center and typically 12 ft or 6 ft long, 4 ft cross tees between them, https://kanopibyarmstrong.com/pages/how-to-install-drop-ceilings (retrieved 2026-10-18); NIST SP 811 (2008), Appendix B: 1 ft = 0.3048 m exactly, 1 ft² = 0.09290304 m², https://www.nist.gov/pml/special-publication-811 (retrieved 2026-10-18)
- Room length 20 ft, Room width 14 ft, Grid 2 × 4 ft, Main tee and wall angle length 12 ft gives Ceiling panels 40, Main tees 6, 4 ft (1200 mm) cross tees 36, 2 ft (600 mm) cross tees 0, Wall angle pieces 6.
- Room length 16.4 ft, Room width 10.83 ft, Grid 600 × 600 mm, Main tee and wall angle length 11.81 ft gives Ceiling panels 54, Main tees 4, 4 ft (1200 mm) cross tees 24, 2 ft (600 mm) cross tees 27, Wall angle pieces 5, Ceiling area (m²) 16.5.
How it works
The page lays out a grid. The module m is 2 ft for the 2 × 2 and 2 × 4 ft grids, and 0.6 m (600 mm) for the metric grids. Main tees run along the room length L, 2m apart (4 ft or 1.2 m), starting from one wall; cross tees run across the width W every m along the length. Armstrong's Kanopi install guide puts main beams 4 ft on center, with 4 ft cross tees between them; main tees typically come 12 ft or 6 ft long, and the piece length defaults to 12 ft. ⌈x⌉ means x rounded up to a whole number.
- Columns = ⌈L ÷ m⌉, the panels along the length
- Cells = ⌈W ÷ 2m⌉, the 4 ft (1.2 m) openings across the width
- Halves = ⌈W ÷ m⌉, the 2 ft (0.6 m) panels across the width
- Ceiling panels = columns × halves for 2 × 2 and 600 × 600; columns × cells for 2 × 4 and 600 × 1200
- Main tees = (cells − 1) × ⌈L ÷ piece length⌉
- 4 ft (1200 mm) cross tees = (columns − 1) × cells
- 2 ft (600 mm) cross tees = columns × (halves − cells) for a square grid, 0 otherwise. Only openings wider than 2 ft (0.6 m) get one.
- Wall angle pieces = ⌈2 × (L + W) ÷ piece length⌉
- Ceiling area = L × W, in ft² and m²
Every cut border panel counts as a whole panel.
Exact arithmetic. Each length is read as the exact decimal you typed, in its unit, and every count is rounded up from the exact value.
Rounding. Counts are whole numbers; the area shows in ft² with at most 1 decimal and in m² with at most 2, rounded half up.
Assumptions
- The room is a rectangle; for an L-shaped room, work out each rectangle and add them.
- The grid starts against one wall. Balancing the borders, so both edges get equal cut panels, can add a row of panels and tees.
- Hanger wire, fasteners, and spare panels are not counted.
- Room sides are 0.3 m to 300 m; the piece length is 1 m to 10 m.
Worked examples by hand
A 20 × 14 ft room on a 2 × 2 grid, 12 ft pieces. Columns ⌈20 ÷ 2⌉ = 10; cells ⌈14 ÷ 4⌉ = 4; halves ⌈14 ÷ 2⌉ = 7. Panels 10 × 7 = 70. Main tees (4 − 1) × ⌈20 ÷ 12⌉ = 3 × 2 = 6. 4 ft cross tees (10 − 1) × 4 = 36. 2 ft cross tees 10 × (7 − 4) = 30. Wall angle ⌈68 ÷ 12⌉ = 6. Area 280 ft².
The same room on a 2 × 4 grid. Panels 10 × 4 = 40; main tees 6, 4 ft cross tees 36, no 2 ft cross tees, wall angle 6.
A 5 × 3.3 m room on a 600 × 600 mm grid, 3.6 m pieces. Columns ⌈5 ÷ 0.6⌉ = 9; cells ⌈3.3 ÷ 1.2⌉ = 3; halves ⌈3.3 ÷ 0.6⌉ = 6. Panels 9 × 6 = 54. Main tees 2 × ⌈5 ÷ 3.6⌉ = 4. 1200 mm cross tees 8 × 3 = 24; 600 mm cross tees 9 × 3 = 27. Wall angle ⌈16.6 ÷ 3.6⌉ = 5. Area 16.5 m².
Other questions people ask
How many ceiling tiles do I need for a drop ceiling?
Count the panels across each way, rounding up, and multiply. A 20 × 14 ft room on a 2 × 2 grid is 20 ÷ 2 = 10 panels one way and 14 ÷ 2 = 7 the other: 70 panels, with each cut border panel counted whole. On a 2 × 4 grid it is 10 × 4 = 40.
How do I lay out a drop ceiling grid?
Wall angle goes around the room at ceiling height. Main tees run the length of the room, usually across the joists, 4 ft apart. Cross tees 4 ft long clip between the mains every 2 ft, and for a 2 × 2 grid, 2 ft cross tees split each 2 × 4 opening in half.
How many main tees do I need?
Find the number of main tee lines, the room width ÷ 4 ft rounded up, minus 1, then multiply by the pieces each line needs: the room length ÷ 12 ft, rounded up. A 20 × 14 ft room needs 3 lines of 2 pieces, so 6 main tees.
How much wall angle do I need?
Measure the perimeter and divide by the piece length, rounding up. A 20 × 14 ft room has a 68 ft perimeter, so it needs 68 ÷ 12 = 5.7, which is 6 pieces of 12 ft wall angle.
Is 2 × 2 or 2 × 4 better?
2 × 4 needs fewer panels and no short cross tees, so it costs less. 2 × 2 looks more finished and its panels are easier to handle. Both use the same main tees and 4 ft cross tees.
Are metric ceiling tiles the same size as 2 × 2 ft tiles?
No. A 600 mm tile is 23.6 in, a little smaller than 24 in (609.6 mm), so metric and US grids do not mix. Pick the grid that matches the panels you will buy.