Paint Weight Calculator

How the paint weight calculator works

Paint weight is volume times density, and nothing else. The calculator takes how much paint you have and how heavy that paint is per unit of volume, multiplies the two, and gives you the weight of the liquid in pounds or kilograms. People use it to plan a courier booking or a pallet, to check what a van or a scaffold lift is carrying, or to work out whether a stack of tins can go up a loft ladder in one trip.

The catch is in the density, because it changes from product to product. Water weighs about 1 kg per litre. Paint is heavier because of the pigments and fillers suspended in it, and how much heavier depends on the formulation. So the most useful thing you can do before trusting any result is look up the figure for the tin in your hand.

Finding the density for your paint

Every serious manufacturer prints it on the technical data sheet (TDS) or the safety data sheet. US sheets usually call it weight per gallon and give it in pounds. Benjamin Moore's sheet for Regal Select semi-gloss lists 10.8 lb per gallon, and the flat finish of the same range lists 11.2 lb. European, UK and Australian sheets give density in kg/L or g/cm³, or quote a specific gravity; for practical purposes a specific gravity of 1.30 is 1.30 kg/L.

If you have one figure and need the other, the conversion is fixed. One pound per US gallon is 0.119826 kg/L, the factor listed in NIST Special Publication 1038, which also defines the US gallon as 231 cubic inches (3.785 litres) and the pound as 0.45359237 kg. So 10.8 lb/gal is 1.294 kg/L and 11.2 lb/gal is 1.342 kg/L. Going the other way, multiply kg/L by 8.345: the metric default of 1.30 kg/L is 10.85 lb/gal.

No data sheet to hand? Weigh a full tin, weigh the same tin once it's empty, and divide the difference by the volume on the label. It takes two minutes on a set of bathroom scales and beats any generic figure.

Worked examples in gallons and litres

The imperial default is a single US gallon at 10.8 lb/gal, which weighs 10.8 lb, or 4.90 kg. A 5 gallon pail of the flat finish at 11.2 lb/gal holds 56 lb of paint (25.40 kg). On the metric side the default is a 5 litre tin at 1.30 kg/L: 6.5 kg, or 14.33 lb. A 10 litre tub of the same paint is 13 kg.

Larger orders work the same way. Forty gallons at 11.2 lb/gal is 448 lb of paint, just over 203 kg, which is pallet territory for most carriers. Mixed orders need one sum per product, because the calculator applies a single density. Three gallons of primer at 12.0 lb/gal plus ten gallons of finish at 10.8 lb/gal is 36 + 108 = 144 lb. In metric, four 10 litre tubs of emulsion at 1.35 kg/L plus two 5 litre tins of gloss at 1.20 kg/L comes to 54 + 12 = 66 kg.

Which gallon?

The gallon here is the US gallon of 3.785 litres. The imperial gallon still seen on older British tins and in some Commonwealth trade talk is 4.546 litres, about 20% bigger. If a figure is quoted per imperial gallon, convert it to litres and use the metric side of the calculator instead: one imperial gallon of 1.30 kg/L paint weighs 5.91 kg (13.03 lb), against 10.85 lb for a US gallon.

What the number leaves out

The result is the weight of the paint only. Cans, pails, lids, handles, boxes and pallets all add to what a carrier will weigh, and plastic and steel containers differ, so weigh one empty container or ask the supplier for the packed weight before you book. The figure also says nothing about how many packages the order should be split into. Carriers set their own per-parcel weight limits, and they vary by company and country, so check the booking rules for the service you plan to use.

How the paint is classed matters as much as its weight. Paint that meets the definition of a flammable liquid, which in practice usually means solvent-borne paint, lacquer, varnish or thinners rather than water-based emulsion, is listed as UN 1263, Class 3, in the US Hazardous Materials Table at 49 CFR 172.101. UN numbers apply internationally, so the same product is dangerous goods for road, air and sea almost everywhere. The safety data sheet says whether your tin is regulated, and your carrier will tell you what packaging and paperwork they need.

Load planning on site

Weight matters on a scaffold, a mobile tower or a roof as much as in a van. A working platform has a rated load, and several pails of paint, a painter and their kit add up faster than people expect: ten 5 gallon pails at 11.2 lb/gal is 560 lb of paint before the pails themselves. Check the platform's rating against the total, not against one pail at a time. The same arithmetic tells you when to stop carrying pails by hand. The UK Health and Safety Executive's manual handling guide uses 25 kg for men and 16 kg for women as its low-risk filter for a load held close to the body between knuckle and elbow height, and says plainly that these are not safe limits. A single 5 gallon pail of the flat finish is 25.4 kg of paint alone.

If you are still working out how much paint the job needs, start with the coverage calculators in this category, then bring the total volume back here for the weight.