Buyer guide

How to work out the total weight of a framed piece

A framed picture is a stack of parts, and its weight is the sum of those parts. This guide shows how to add them up, with a worked example you can copy.

Add the weight of the frame, the glazing, the mat, the backing board and the print. Weigh the frame, mat and backing on a scale. Work out glazing from its volume times its density: about 2,500 kg per cubic metre for glass [1][2] and about 1,190 kg per cubic metre for acrylic [3]. Round the total up, then choose hanging hardware rated for at least 1.5 times it [4].

The parts that add up

Hanging guidance from a picture-frame retailer tells you to add the weights of the frame, glazing, mat board, mounting board and artwork, then round up [4]. The hardware rating then follows from that number [4].

The glazing is the one part you can calculate instead of weighing. The rest are easiest to weigh directly, on a kitchen or postal scale, one part at a time.

If you specify a range for your brand, record the total once per size and glazing thickness in your spec sheet. Our guide on frame materials compares polystyrene, wood and aluminium frames.

Glazing weight: density times thickness

Mass is volume times density. For a flat sheet, volume is width times height times thickness, so the rule is: mass (the weight you put on a scale, in kg) = width x height x thickness x density. Use metres for every length and the answer comes out in kilograms. Glazing thickness is often given in millimetres, so convert first: 2 mm is 0.002 m.

Soda-lime float glass is listed at 2,440 to 2,520 kg/m3 in the density table of [1], which also calls 2.5 g/cm3 (2,500 kg/m3) the standard reference value. A glass supplier's information sheet lists soda-lime glass at 2,500 kg/m3 at 18 C [2]. For acrylic, the manufacturer's technical information lists PLEXIGLAS GS (cast acrylic) at 1.19 g/cm3 [3], which is 1,190 kg/m3. This guide uses 2,500 and 1,190. Because published densities vary a little, treat the result as an estimate and check it against a scale once you have a sample.

With 1,190 kg/m3 for acrylic [3] and 2,500 kg/m3 for glass [1][2], a sheet of acrylic has roughly half the mass of a glass sheet of the same size and thickness (1,190 / 2,500 is about 0.48). Weight also rises in step with thickness, so a sheet twice as thick weighs twice as much. For the other trade-offs between the two, see acrylic vs glass glazing for picture frames.

A worked example (assumed sizes)

Take a frame with a 0.30 m x 0.40 m glazing sheet, 2 mm thick. The sizes and the weights of the non-glazing parts below are assumed for illustration only. Replace them with your own scale readings.

Figure: the four steps of the guide's worked example, from glazing weight to hanging-hardware rating. Only the glazing is calculated; the other weights in the example are assumed.

Glass: 0.30 x 0.40 x 0.002 = 0.00024 m3. Times 2,500 kg/m3 = 0.60 kg [1][2].
Acrylic: 0.00024 m3 times 1,190 kg/m3 = 0.2856 kg [3].
Assumed, from a scale: frame 0.50 kg, mat 0.15 kg, backing board 0.25 kg, printed paper 0.05 kg.

The sums are: glass version 0.60 + 0.50 + 0.15 + 0.25 + 0.05 = 1.55 kg; acrylic version 0.2856 + 0.95 = 1.2356 kg, where 0.95 kg is the frame, mat, backing and paper together. Rounding up to the next 0.1 kg (the retailer says only to round up [4]; the step size is our choice for this example) gives 1.6 kg and 1.3 kg. Swapping glass for acrylic saves 0.60 - 0.2856 = 0.3144 kg, shown as 0.31 kg, on this one frame, and the saving grows with size. Rounding up keeps the estimate on the safe side, because real parts vary a little from the figures you used.

Total weight of the example frame, 0.30 m x 0.40 m, 2 mm glazing
Part	How found	With glass (kg)	With acrylic (kg)
Glazing	Volume x density [1][2][3]	0.60	0.2856
Frame	Weighed (assumed)	0.50	0.50
Mat	Weighed (assumed)	0.15	0.15
Backing board	Weighed (assumed)	0.25	0.25
Printed paper	Weighed (assumed)	0.05	0.05
Total	Sum of parts	1.55	1.24
Rounded up	Round up to next 0.1 kg (step is our choice) [4]	1.6	1.3

Only the glazing row is calculated. The other weights are assumed for illustration and are not measured values. Totals are summed at full precision (acrylic 1.2356 kg), shown to two decimals, and rounded up to the next 0.1 kg, a step we chose for this example; the retailer says only to round up [4].

Weighing the frame, mat and backing

Do not guess these. Frame weight depends on the material and profile, so weigh a sample cut to the finished size. Mat and backing board weights depend on thickness and area, so weigh them too, or weigh a known area and scale up.

Weigh each part dry and separately, then add. Do not weigh the finished piece only, so you can see which part to change.
Weigh to the nearest gram on a small scale and keep full precision until the final total.
If the piece ships boxed, weigh the packed carton separately. Packaging is a different number. See private-label packaging and inserts.

From total weight to hanging hardware

Once you have the total, pick hardware with headroom. The same retailer's rule is a rating of at least 1.5 times the total, and it lists wire rated for 1.5 times the frame's total weight [4]. For the example, round 1.55 kg up to 1.6 kg, then 1.6 x 1.5 = 2.4 kg, so choose wire rated for at least 2.4 kg [4]. This 1.5 times margin is the advice of one retailer [4]; always follow the rating printed on the hardware you buy.

For D-ring sizing by weight band and wall fixings, read our guide on hanging hardware and wall load for frames and boards.

How this applies when you work with us

To discuss a size and glazing choice, see how our quotes work or contact us. We reply within 1 business day.

Questions buyers ask

How much does a framed picture weigh?

Weight is the sum of the frame, glazing, mat, backing and print. The glazing can be calculated from volume times density, and the other parts should be weighed on a scale. Our worked example shows the method with assumed numbers, not measured values.

How do I convert glazing thickness from millimetres?

Divide by 1,000 to get metres, so 2 mm becomes 0.002 m. Then multiply width, height and thickness in metres to get volume in cubic metres, and multiply by density in kg/m3 to get kilograms.

Is acrylic lighter than glass?

Yes, by density. Acrylic is about 1,190 kg/m3 [3] against about 2,500 kg/m3 for glass [1][2], so a sheet of acrylic has roughly half the mass of a glass sheet of the same size and thickness.

What if I change the glazing thickness?

Glazing weight is proportional to thickness, so moving from 2 mm to 3 mm multiplies the glazing row by 1.5. Recalculate that row with the new thickness in metres and leave the other parts unchanged unless the frame or mat changes.

Do I need to weigh the frame, or can I calculate it?

Weigh it. Frame weight depends on the material and profile, and mat and backing weights depend on their thickness, so a scale reading is more reliable than an estimate. Calculating works well only for the flat glazing sheet.

What wire rating should I use?

The retailer's rule is a rating of at least 1.5 times the total weight [4]. For the example, the total rounded up is 1.6 kg, so 1.6 x 1.5 = 2.4 kg. Follow the rating printed on the product.