Efficiency

Efficiency is a measure of the cost per experience of a training method, factoring in opportunity cost (the amount of profit that was sacrificed by pursuing the training method instead of spending the same amount of time earning money). A simple formula can be used to decide whether or not it's worthwhile to spend more money on a faster training method.

Efficiency is often used in the context of evaluating, based on how valuable you perceive your time to be, two different methods to train a skill for which their experience per hour and profit per hour are known. If one method gives more experience per hour than the other and also costs less (or gives more profit), then there is no question which method is more efficient. However, if one method gives faster experience than the other but costs more (or gives less profit), then the most efficient method depends on how much the player perceives their value of time to be. It is possible to calculate which method is more efficient for a player with a known value of time. It's also possible to calculate at what value of time the two methods are equally efficient.

Efficiency cannot take into account enjoyment of the game, and therefore a method considered "most efficient" may not necessarily be the preferred method.

When calculating the cost per experience of any training method, generally all raw material costs used in the calculators are based on real-time prices from the Grand Exchange Market Watch. This assumes that the player is buying items from the Grand Exchange, even if these items are easily obtainable from alternative locations.

This is due to the fact that using an item as a raw material prevents the player from selling that item on the Grand Exchange, thereby effectively "costing" the player the amount of money they could have sold it for. In business, this concept is called opportunity cost and should be considered when calculating the actual cost using raw materials.

For example:

When prayer potions are made, snape grass is one of the ingredients (raw material) used for making this potion. Snape grass can easily be found on the Hobgoblin peninsula, south-west of the Crafting Guild, which is south-west of Falador, and also on Waterbirth Island. However, the player could sell the snape grass on the Grand Exchange for 1,080 coins each. So, using it to make Prayer potions has effectively cost them 1,080 coins for each potion made, even though they got snape grass free.

Furthermore, picking up the snape grass to make the potions will have the opportunity cost of time. This is a very important concept to understand because it will greatly affect your profits. The time you spend picking up snape grass could have been spent on other money-making methods which would be more beneficial. For example, the player could spin flax instead of picking snape grass, then sell the flax and buy more snape grass than they would have been able to pick in the same amount of time.

The same concept applies to any ores mined or any animal hides collected instead of being bought from the Grand Exchange. This may sound counter-intuitive, but ignoring it distorts the actual cost of making items and gives incorrect figures. That said, while opportunity cost must be considered in a microeconomic cost-benefit model, it is important to note that market forces sometimes make selling the raw materials (also known as "inputs") difficult. It might take a long time, for example, to sell iron ores, but superheating them into iron bars for experience and profit could yield a faster turn-around on the time investment. In a macroeconomic sense, players must evaluate how long they wish to spend, and how much money they have on hand before deciding whether to harvest raw materials themselves, or purchase them outright. Generally, one will save time by purchasing the raw materials, but one must invest more money up-front, and in many instances will not turn a profit. Conversely, it will take one longer to harvest raw materials but the initial investment is much lower (provided, of course, that you are capable of acquiring the raw materials you need in the first place) but in many instances to overall profit potential is higher because you are reducing your input costs.

If you are harvesting your raw materials, simply calculate with a GE price of 0 for whatever you happen to be harvesting on your own. For example:

Raw fish		GE Price	Cooked fish		GE Price	Profit/Loss	Profit/XP
	Raw shrimps	0		Shrimps	22	22	0.73

If buying the materials, it is possible to make or lose nothing:

Raw fish		GE Price	Cooked fish		GE Price	Profit/Loss	Profit/XP
	Raw shrimps	22		Shrimps	22	0	0

Or to lose money:

Raw fish		GE Price	Cooked fish		GE Price	Profit/Loss	Profit/XP
	Raw shrimps	44		Shrimps	22	−22	−0.73

Raw shrimps actually cost 24 on the GE, above prices are examples only.

See the calculators in the next section to test these formulas with your own live data.

One way to compare two methods for training a skill is to calculate the efficiency ratio E for each method, in coins per experience, by using the equation:

where:

• V is your value of time (coins per hour). This comprises not only the profit per hour if you spent the time moneymaking, but may also include the value of experience.
  • For example, if double nature runes via the Abyss at 91 Runecrafting is 900,000 profit per hour, someone with 91 Runecrafting should value their time at at least 900,000 coins per hour – but may wish to add on some arbitrary additional amount to take the Runecrafting experience gained into consideration.
• P is the positive profit per hour of the method being considered. If it costs money, P is negative.
• X is the experience per hour of the method being considered.
• E, with units of coins per experience, denotes how many coins one experience point of that skill is worth using this training method, assuming that coins and time are freely converted in both ways. For example, if E equals 5, then one is indifferent between 5 coins and 1 experience in that skill; one would gladly pay 5000 coins for 1000 experience.
  • A lower value indicates a more efficient method (meaning it costs you less, when the value of your time is taken into account). A value of 0 means this is the most efficient method possible for you; there is nothing else more profitable you could do with your time.
  • If E is negative, then actually, one has not correctly assigned the value of V. For example, suppose that one set V = 650,000 and wanted to compute the efficiency of Abyss nature crafting like above. One would compute E = (650000-900000)/(42000) or about -6.0. This is nonsensical because a rational person would always prefer a gain of 1 Runecrafting experience to losing 6 coins. A value of V = 1,100,000 (or any amount greater than or equal to 900,000) is plausible; it yields a rating of about 4.8.

This equation is most effective for comparing methods that give experience in a single skill. Methods that give experience in multiple skills can only be used if only one type of experience is being considered – however, the experience in the secondary skill would give the method an edge in value, compared to methods that only give experience in one skill.

This equation also cannot be used to compare training methods from different skills; it can only be used to compare methods to train the same skill.

Now suppose that you're not sure what to value your time at – many people don't have any specific idea. It is possible to compare two methods and get a value of time (coins per hour) at which one method becomes better than the other. This could help you choose which method to use.

The value of time at which two methods for training the same skill become equally efficient is given by the equation

where:

• V is the value of time per hour at which the two methods are equally efficient.
• P₁ is the profit per hour of method 1.
• P₂ is the profit per hour of method 2.
• X₁ is the experience per hour of method 1.
• X₂ is the experience per hour of method 2.

Typically the faster and more expensive method is used for method 2.

To make this even more clear, the calculator below will print a result in a human-readable sentence.

Many skills have both click-intensive methods with higher experience or profit per hour and more passive methods with lower experience or profit per hour. One method requires your full attention while the other can be done in the background with little to no attention. An example of a passive activity might be zero-time fletching in between agility obstacles, or fishing afk while working in real life.

In this situation, the passive activity could be assumed to give infinite experience or profit per hour because it takes none of your active time; it just comes at the expense of a different choice of passive activity. This breaks the equations above; there are a few different ways to rectify this depending on your goals:

• Assign an arbitrary multiplier to the experience or profit gained by passive activities, such as 10x, to see how it affects the equation.
• Determine a deadline by which you want to attain the experience or profit; if the passive activity will take too long, supplement with active alternatives.
• Pick two activities instead of one: one to perform while playing actively, and another to perform while playing passively.
• Weigh all of your different passive options against each other (even across different skills), and choose the best few; always do these while passive, and ignore the other passive alternatives.

Templates used
Calculator:Efficiency ratio/Template

This dynamic calculator requires JavaScript. This page takes user input via JavaScript and may use changing prices from the Grand Exchange Market Watch.

Calculates an efficiency ratio used to compare multiple training methods for a single skill, factoring in the opportunity cost of not spending that time making money.

is how many coins one experience point of that skill is worth using this training method. For example, if equals 5, then one is indifferent between 5 coins and 1 experience in that skill; one would gladly pay 5000 coins for 1000 experience.

 template = Calculator:Efficiency ratio/Template
 form = efficiencyRatioCalcForm
 result = efficiencyRatioCalcResult
 param = value|Best moneymaking profit per hour||number|-100000000-100000000
 param = experience|Training experience per hour||int|
 param = drop|Training cost measure||select|Profit per hour,Coins per XP
 param = profit|Profit (positive) or loss (negative)||number|-100000000-100000000,0.001

Templates used
Calculator:Efficiency method comparison/Template

This dynamic calculator requires JavaScript. This page takes user input via JavaScript and may use changing prices from the Grand Exchange Market Watch.

Calculates which of two methods is more efficient to train a single skill, taking into account what else the player could do using the time saved.

 template = Calculator:Efficiency method comparison/Template
 form = efficiencyCompareCalcForm
 result = efficiencyCompareCalcResult
 param = experience1|Experience per hour (Method 1)||int|
 param = drop1|Cost measure (Method 1)||select|Profit per hour,Coins per XP
 param = profit1|Profit or loss (Method 1)||number|-100000000-100000000
 param = experience2|Experience per hour (Method 2)||int|
 param = drop2|Cost measure (Method 2)||select|Profit per hour,Coins per XP
 param = profit2|Profit or loss (Method 2)||number|-100000000-100000000