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The Food Index is made up of a weighted average of all of the current foods listed in the Market Watch, with the starting date of this average on 12 January 2008, at an index of 100. The overall rising and falling of food prices is reflected in this index.

While specialised for just watching food prices, it is set up and adjusted in a manner similar to the Common Trade Index, and the divisor may be adjusted to include new food added by Jagex (see the FAQ for more information).

As of today, this index is 227.42 Down -1.88

Historical chart

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Summary

Any suggested changes to this index should be added to the talk page.

  • Start date: 12 January 2008 (at index of 100)
  • Index today: 227.42
  • Change today: Down -1.88
  • Number of items: 19 (last adjusted on 12 January 2008)
  • Index divisor: 19.0000 (last adjusted on 12 January 2008)

List of items

This is the current list of items included in this index:

Icon Item Price Direction Low Alch High Alch Limit Members Details Last updated
BassBass188
Unchg
10816210,000P2P iconview35 days ago
BreadBread551
DownDown
9141,000F2P iconview35 days ago
CakeCake186
Unchg
20301,000F2P iconview35 days ago
CavefishCavefish1,262
Down
14021010,000P2P iconview35 days ago
Chocolate cakeChocolate cake476
Down
28421,000F2P iconview35 days ago
Great white sharkGreat white shark1,047
UpUp
13019510,000P2P iconview36 days ago
LobsterLobster143
Up
10716010,000F2P iconview36 days ago
MonkfishMonkfish278
Down
9213810,000P2P iconview36 days ago
RocktailRocktail1,891
Up
24036010,000P2P iconview36 days ago
SalmonSalmon37
Unchg
355210,000F2P iconview36 days ago
Saradomin brew (4)Saradomin brew (4)6,172
Down
801201,000P2P iconview36 days ago
SharkShark912
Down
12018010,000P2P iconview36 days ago
Strawberries (5)Strawberries (5)650
Unchg
0010,000P2P iconview36 days ago
SwordfishSwordfish204
Down
16024010,000F2P iconview36 days ago
TunaTuna37
Unchg
487210,000F2P iconview36 days ago


Adjustments

20 May 2015
Item Base date Base price Price on adjustment date Comments
Lobster 25 January 2008 175 196 Unchanged
Bass 195 225
Tuna 81 163
Swordfish 272 295
Monkfish 233 336
Shark 657 739
Cake 52 91
Chocolate cake 150 421
Ugthanki kebab 887 810 Removed item
Kebab 32 276
Sea turtle 1,264 2,690
Manta ray 1,794 1,907
Sweetcorn 135 43
Roast bird meat 22 19
Admiral pie 1,031 497
Wild pie 3,491 985
Redberry pie 381 1,280
Garden pie 657 475
Stew 100 1,102
Bread 433 Added item
Strawberries (5) 318
Saradomin brew (4) 9,762
Salmon 80
Cavefish 1,256
Rocktail 1,814
Great white shark 912

Calculations

From the old divisor obtained from the templates:

$ {div}_{\text{old}} = 19.0000 $


We need to calculate a new divisor:

$ {div}_{\text{new}} = {div}_{\text{old}} \times \frac{\sum \left ( \frac{p}{q} \right )_{\text{new}}}{\sum \left ( \frac{p}{q} \right )_{\text{old}}} $


To calculate the new divisor, we need to find:

$ \begin{align} \sum \left ( \frac{p}{q} \right )_{\text{old}} & = \text{sum of ratios prior to change} \\ & = \text{sum of unchanged ratios} + \text{sum of removed ratios} \\ & = \left (\frac{196}{175} + \frac{225}{195} + \dots + \frac{421}{150} \right ) + \left (\frac{810}{887} + \frac{276}{32} + \dots + \frac{1,102}{100} \right ) \\ & = 42.27255853 \text{ (up to 8 d.p.)} \end{align} $


And also:

$ \begin{align} \sum \left ( \frac{p}{q} \right )_{\text{new}} & = \text{sum of ratios prior to change} - \text{sum of removed ratios} + \text{sum of added ratios} \\ & = \sum \left ( \frac{p}{q} \right )_{\text{old}} - \text{sum of removed ratios} + \text{number of added items} \\ & = 42.27255853 - \left ( \frac{810}{887} + \frac{276}{32} + \dots + \frac{1,102}{100} \right ) + 7 \\ & = 19.49428715 \text{ (up to 8 d.p.)} \end{align} $


Thus, the new divisor is:

$ \begin{align} {div}_{\text{new}} & = {div}_{\text{old}} \times \frac{\sum \left ( \frac{p}{q} \right )_{\text{new}}}{\sum \left ( \frac{p}{q} \right )_{\text{old}}} \\ & = 19.0000 \times \frac{42.27255853}{19.49428715} \\ & = 8.7619 \text{ (4 d.p.)} \end{align} $