Weight

The weight of items refers to how heavy they are, and is measured in kilograms (kg). Every item has a weight, although it may be zero (for example, stackable items) or even negative, such as the boots of lightness. Weight is stored as grams, holding 3 points of precision when converted to kilograms.

Players can see the total weight of the items they are carrying on the Equipment Stats screen from the Worn Equipment interface. This will include items they have equipped as well as those carried in the inventory. Many nonstackable items weigh fractions of a kilogram, but the Equipment Stats screen truncates (does not show the decimal portion), so these may appear as zero even though they have some slight weight.

Effects of weight

Carrying more weight causes energy to decrease more quickly. The minimum possible rate of energy loss while running is 0.7 %/tick (when your weight is 0 kg or less), while the maximum possible rate of energy loss is 1.4 %/tick. The rate of decrease of energy per kilogram has been empirically found to be 0.00729166 ± 0.00000004 %/tick/kg, that is, for every kg of weight you add on, the rate of energy loss increases by approximately 0.00729166 %/tick. However, for any given weight, the rate of energy loss is truncated to the nearest hundredth. A consequence of this is that you can carry up to 1.371 kg with exactly the same run energy drain rate as if you were carrying 0 kg.

Players who undertake activities requiring a lot of running around would be well advised to minimise the total weight they carry while doing so, since they will be able to run for longer.

Some activities in RuneScape require players to weigh no more/no less than a certain amount. For example, whilst doing the Pirate Pete part of the Recipe for Disaster quest, players must be carrying no more than 27 kg to dive off Port Khazard. In the quest Temple of Ikov, players must weigh less than 0 kg to cross a bridge, this is just after having received the boots of lightness. Also, in order to use the Balloon transport system, players must be carrying less than 40 kg. To get into Movario's base (during and after While Guthix Sleeps) you need to weigh more than 1 kg.

Extrema

Heaviest items

This lists only the 30 heaviest items in RuneScape; a complete list of all items can be found here.

Item		Weight (kg)
	Naphtha mix (sulphur)	32
	Barrel of naphtha	32
	Barrel of coal-tar	32
	Doc's broken shieldbow	32
	Doc's cracked orb	32
	Doc's broken dagger	32
	Doc's old clothes	32
	Doc's rotten timber	32
	Sandstone (32kg)	32
	Barrel bomb	32
	Crate with zanik	32
	Ana in a barrel	32
	Aminishi soil	32
	Cannon barrel	32
	Broken cannon	32
	Naphtha mix (quicklime)	32
	Barrel bomb (unfused)	32
	Astral token	32
	Big rock	32
	Toxic naphtha	32
	Naphtha apple mix	32
	Stone slab	32
	Steel girder	32
	Iron girder	32
	Gold helmet	31.751
	Zanik (item)	30
	Barrelchest anchor	30
	Golden goblin	30
	Sandstone body	30
	Bundle o' kegs	30

Heaviest item per slot (members)

Item		Slot	Weight (kg)
	Gold helmet	Head	31.751
	Expert skillcape shard bag	Cape	10
	Seal of passage	Neck	4.535
	Tirannwn quiver 4	Ammo	1
	Crate with zanik	Two-hand	32
	Granite body	Body	22.679
	Granite legs	Leg	15.875
	Penguin gloves	Hand	4.535
	Lucky Bandos boots	Feet	6
	Victor's bronze ring	Ring	0.453
	Statue collection bag	Pocket	10

Heaviest item per slot (free-to-play)

Item		Slot	Weight (kg)
	Five barrels	Head	22.679
	Pathfinder cape	Cape	1.814
	Manspeak amulet	Neck	1.36
	Wicked pouch	Ammo	1
	Stone of power	Two-hand	30
	Adamant platebody (h4)	Body	11.339
	Adamant platelegs (h5)	Leg	10.432
	Penguin gloves	Hand	4.535
	Penguin feet	Feet	4.535
	Victor's bronze ring	Ring	0.453
	Challenge shard	Pocket	0.907

Lightest item per slot (members)

Item		Slot	Weight (kg)
	Exoskeleton headband	Head	-2
	Wicked cape	Cape	-6
	Agile top	Body	-12
	Agile legs	Leg	-10
	Hardened penance gloves	Hand	-7
	Boots of lightness	Feet	-4.535

Lightest item per slot (free-to-play)

Item		Slot	Weight (kg)
	Silver athlete's hat	Head	-0.907
	Infinity ethereal body	Body	-10
	Infinity ethereal legs	Leg	-8
	Silver athlete's gloves	Hand	-0.907
	Silver athlete's shoes	Feet	-0.907

A small number of free items are with zero weight but some of them are with "fake" zero weight, that will increase energy loss rate while running even if the equipment screen shows 0 kg otherwise.

Trivia

• Processing many of the items changes the weight of them not according to the real world, for example: an inventory of 14 bowstrings and 14 yew longbows (u) weighs 7 kg more than their combined product of 14 yew longbows (actual stringing of a bow would reduce little to no weight), however some cases follow an actual model, like a steel platebody weighs less than the five steel bars used to make it, as scrap metal is disposed in smithing armour.
• Sometimes RuneScape item weights are unrealistic - for example, the cannonball, which is stackable, weighs 0 kg, when one would expect it to be quite heavy. This is presumably so that the Dwarf multicannon is easier to use. There is also another rather amusing factor - no matter how many Coins you carry in your inventory - which can be great in amount - you can never increase your weight, which will stay the same. However, this could be due to the very inherent magical nature of Gielinor itself, or just a measure of exchanging cash into convenient forms like cheques in the real world.
• There once was a glitch that activated weight-lowering items without having to wear them. A player could have a full inventory of spottier capes and weigh about -126 kg. The glitch is now fixed.
• Once a group of armour components are compressed as a set at the Grand Exchange, the set weighs 0 kg, instead of the combined weight of the individual pieces. This could be because of the fact that a compressed set acts like a note containing all the items of the set.
• The weights of some categories of items seem to indicate that they are or were in the past stored in pounds, instead of kilograms. Batwing legs, for example, weigh exactly 0.453 kg, which is (to the nearest thousandth) exactly the number of kilograms in one pound. Other armours and metals have weights which are near multiples of 0.453 kg, which means that their weights are also very nearly whole numbers of pounds.
• The kilogram is actually not a unit of weight, but a unit of mass. These terms are often confused; see, for example, the Wikipedia article on "Mass versus weight".