Red Rods
Red rods are ten wooden rods, 10 cm to 1 m long in 10 cm steps, for the Sensorial lesson in length at about 3 to 5. Sets cost $58.95 to $183.40 at the three US sellers we checked on October 2, 2026. A homemade set is ten lengths of square timber cut to size and painted red.
The first lesson with it is Red Rods (Long Rods). Not sure your child is ready for it? Two minutes of questions place your child on the sequence.
| Area | Sensorial |
|---|---|
| Used in | |
| From age | 3 to 5 years |
| Make it | Possible to make with some effort |
| Buy it | About $59 to $183 (noted ) |
What the red rods are for
The rods change in one dimension only. Every rod has the same square end, so the child has nothing to judge but length. Montessori found them the hardest of her three size materials, after the pink tower and the brown stair.
Her 1912 rods were painted in alternating red and blue sections and did the counting work too. Her 1914 handbook also lists green rods. The plain red set, kept apart from the number rods, is the later tradition.
| Part | What it looks like |
|---|---|
| Rods | Ten, from 10 cm to 100 cm in 10 cm steps |
| Section | 2.5 cm square on Montessori Outlet's set; 3 cm in Montessori's 1912 book, 4 cm in 1914 |
| Finish | Red paint; Nienhuis lists maple under it |
| Storage | Flat on a low shelf or in a rack, longest at the back |
The lessons that use the red rods
Red Rods (Long Rods)
3 to 5 yearsLaying ten rods, 10 cm to 1 m long, side by side from longest to shortest, to judge differences in length by eye.
Buying one: 5 listings checked October 2, 2026
| Seller and set | Made of | Price |
|---|---|---|
| Montessori OutletLong Red Rods (510300110)Ten solid rods, 2.5 cm square, 10 cm to 1 m. Market price shown $179.80. In stock. | Not stated | $58.95 |
| Alison's MontessoriRed Rods, Made in Thailand (S05)Sale price; regular $66.00. Ten rods, 10 cm to 1 m. | Wood, painted red | $59.40 |
| Alison's MontessoriRed Rods, Premium Quality (PS04)Ten rods, 10 cm to 100 cm. Made in Sri Lanka. | Wood, painted red | $151.00 |
| NienhuisThe Red Rods (002600)Ten solid rods, 10 cm to 1 m. US store price. | Maple | $183.40 |
| The Montessori RoomRed RodsCanadian store. Sold as a budget version; an AMI-approved GAM set is $199.99 CAD. | Solid wood | $114.99 CAD |
- The two cheapest sets, Montessori Outlet's at $58.95 and Alison's Thailand-made set at $59.40, cost about a third of Nienhuis's maple set. All three are the same ten lengths.
- Already own the number rods? Wait. Montessori's 1912 school used one set of red and blue rods for both jobs.
- Kid Advance's page returned an error for us, Montessori Services doesn't sell red rods, and Amazon's search page wouldn't load, so none of the three is in the table.
- The Montessori Room in Canada sells two sets: a budget set at $114.99 CAD and an AMI-approved set by GAM at $199.99 CAD.
Making the red rods at home
What to gather
- Three 2 m lengths of 2.5 cm square hardwood strip (5.5 m of rod in all, with offcuts to spare)
- A fine-toothed saw and a miter box, or a chop saw
- A tape measure and a small square
- Sandpaper, 120 and 220 grit
- Red non-toxic paint and a clear water-based finish
| Piece | Size and marking | How many |
|---|---|---|
| Long rods | 2.5 cm square; 100, 90, 80, 70 and 60 cm | 5 |
| Short rods | 2.5 cm square; 50, 40, 30, 20 and 10 cm | 5 |
- 1Plan the cuts so each 2 m strip carries rods that add up to less than 2 m: 100 and 90; 80, 70 and 40; 60, 50, 30, 20 and 10.
- 2Cut the longest rods first. A rod cut short can still become a shorter one.
- 3Check every rod against the 10 cm rod: it should fit along it a whole number of times, with nothing over.
- 4Sand the ends square and soften every edge slightly.
- 5Paint red in two thin coats, seal, and lay the set out as a stair to check that every step is the same.
Keeping a full set on the shelf
- Store the rods flat. A long rod leaned in a corner for months can bow, and a bowed rod spoils the stair.
- Touch up chips with non-toxic paint. A bare patch draws the eye away from the one thing the rods are for, which is length.
Questions parents ask about the red rods
How long are Montessori red rods?
Ten rods from 10 cm to 1 m, each 10 cm longer than the one before. Montessori Outlet's are 2.5 cm square in section; Montessori's own were 3 cm in 1912 and 4 cm in 1914.
Do I need red rods if I have the number rods?
No. The number rods are the same ten lengths with red and blue sections, and Montessori's 1912 school used them for both the length lesson and counting. Buy the red rods if you want the two lessons on the shelf at once.
Where can I buy Montessori red rods?
The table above has the four sellers we could read on October 2, 2026, from $58.95 to $183.40 in the US. Or make a set: three 2 m strips of square hardwood and an afternoon.
Before the red rods, make sure the work before it is solid. The brown stair (broad stair) lesson lists the signs that a child is ready to move on.