What a science fair board costs (and the free way to make one)

A standard 36 × 48 inch tri-fold board cost between $2.99 and $11.89 on the big US stores' own pages when I checked them on 31 October 2026: $2.99 for a cardboard one at Hobby Lobby, $7.99 for foam at Target, $11.89 for corrugated at Target. You don't need the dear one. And if the shops are out on the week of the fair, a big cardboard box and Peabody's free print-at-home kit make a board that a judge reads just as well.

I built the board layout tool and kit on Peabody because the board is often the most expensive part of a project. Most of the projects cost nothing at all. Here is what I found.

Board prices, checked 31 October 2026

All three are 36 × 48 inches, the standard size. Prices are the ones each store's own product page showed that day, before tax, and they change.

A few notes on that table:

• Hobby Lobby's search page showed the cardboard board at $2.99 to $3.99 and the foam board at $8.99 to $11.99; the product pages showed one price each, $2.99 and $8.99.
• Target's black foam board was in stock online. Target also lists a smaller 28 × 40 inch tri-fold at $26.99, marked out of stock. Smaller is not cheaper, and it's not the size a fair expects.
• I tried three more stores and couldn't get a price. Walmart's page asked me to prove I was human, Office Depot's pages timed out, and Dollar Tree's product page came back empty, so I can't tell you what Dollar Tree charges for its tri-fold today. Its listing's title calls it a 27.25 × 39.25 inch board, smaller than the standard one, so check your fair's rules before you buy it.

What else a project costs

Less than the board, usually. Every Peabody project lists the dollars for what most houses don't have, and of the 115 projects, 77 cost nothing. The most expensive is about $4. A few examples, with the project's own figures:

• Which floor makes a ball bounce highest? (1st–5th grade): free. A ball, a tape measure and three floors.
• Does a bigger parachute fall slower? (3rd–8th): free. Three big plastic bags, string, paper clips and a timer.
• Does grass grow best under red, blue or green light? (4th–8th): about $3, for grass seed, potting soil and coloured cellophane.

The other costs are printing and glue: a glue stick, a ruler and a few dozen sheets of printer paper. If your printer has colour, use it for the title and nothing else.

The free way: a box and the kit

You need something stiff, 36 inches tall and about 48 wide, that folds in three. A big cardboard box does it:

1. Find a box with a side at least 36 inches long. Boxes from a TV, a bike or a piece of furniture are about right.
2. A grown-up cuts it into one long strip 36 inches tall: a 24-inch middle with a 12-inch wing on each side. Leave the folds that are already in the box where they fall, or score new ones with a ruler and a blunt pencil.
3. Paint it or cover it with plain paper, so the box's printing doesn't show through.
4. Print the kit. Peabody's board kit prints at true size on ordinary Letter or A4 paper: every card at its real size, the whole board one panel at a time so no page crosses a fold, or just the 13 section titles to cut out (Question, Research, Hypothesis, Variables, Materials, Steps, Data, Results, Graph, Observations, Conclusion, Abstract and Next Time).
5. Check the size and glue. Each page has cut marks, an overlap strip, a name like B3 and a 10 cm bar. Print at 100%, measure the bar, then trim and glue.

The title comes in three kinds of letters, it counts the letters for anyone using stickers, and the QR code can be left off for fairs that don't allow them.

Is a box board allowed?

Usually yes. The rules I've read limit the size and what sits on the table, not what the board is made of. ISEF's Display and Safety Rules give a project 122 cm (about 48 inches) of width and ban liquids at the display; they don't ask for a shop-bought board. If your school's letter says "a tri-fold board", a box cut into three panels is a tri-fold. Your school's sheet wins.

Try tonight

Open the board layout tool. Your child picks a layout, a colour and a title line from three made from their project, then taps each card into place. Print the plan before you buy anything: if the plan fits, any 36 × 48 board will.

Questions grown-ups ask

Should I buy foam or cardboard?

Cardboard is the cheapest and takes glue well. Foam is lighter, stays flat in a damp gym, and costs about $5 more. Both are the same size; see science fair board size for the panel widths.

Can we use the same board two years running?

Yes. Cover last year's board with plain paper and glue the new cards on top.

Do we need the letter stickers?

No. The kit's printed titles do the same job and cost a sheet of paper each. Judges read the words, not the lettering.

Peabody (peabody.kids) is free through the end of 2026, with no ads and no sign-up. The library has free stories by reading level for after the board is done.