Calciro

OSRS Prayer Calculator

Plan an Old School RuneScape Prayer goal using exact level XP thresholds and a manual bone or offering method. Select current and target levels, choose a base XP item and method multiplier, then enter optional cost and speed values.

Offerings Needed
2,929 offerings
XP Remaining
737,954 XP
XP per Offering
252 XP
Expected Items Consumed
2,929 items
Estimated Total Cost
$0
GP per XP
0 GP/XP
Estimated Hours
1.95 hours

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The main result is the expected number of offerings required. The breakdown also shows XP remaining, XP per offering, expected items consumed, estimated cost, GP per XP, and training time.

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How to Use This Calculator

Choose your current and target Prayer levels. Select a bone or enter a custom base XP value. Pick the training method multiplier. For the Chaos altar, enter 0.5 as the expected consumption rate to model the long-run 50% chance to preserve a bone. Enter item cost and offerings per hour only when you want cost and time estimates.

Formula & Methodology

XP remaining equals target XP minus current XP, clamped at zero. XP per offering equals base item XP multiplied by the selected method multiplier. Required offerings are rounded up. Expected items consumed equal offerings multiplied by the consumption rate. Total cost equals expected items consumed multiplied by item cost. GP per XP divides total cost by XP remaining. Estimated hours divide required offerings by offerings per hour.

Dragon bones at a lit gilded altar

From level 70 to 77 Prayer, select Dragon bones (72 base XP), Lit gilded altar (3.5×), and a consumption rate of 1. The calculator uses 252 XP per offered bone and rounds the required offerings up.

This calculator uses manual prices and rates. It does not fetch Grand Exchange prices or Hiscores. Chaos altar preservation is random, so actual supplies consumed can differ from the long-run expectation. Special Varlamore, ash, ensouled-head, spell-rune, and secondary-material costs must be entered manually or represented with a custom XP value.

Old School RuneScape mechanics and item values can change. Verify unusual methods and current prices before buying large quantities.

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Frequently Asked Questions

How does the OSRS Prayer calculator work?
It subtracts your current level XP from target level XP, divides by XP per offering, and rounds up to a whole number of actions.
How do I model the Chaos altar?
Select the 7× XP method and use a 0.5 expected consumption rate to estimate the long-run number of bones consumed.
Does it use live Grand Exchange prices?
No. Enter the current item cost manually if you want a cost estimate.
Can I use a custom Prayer item?
Yes. Choose the custom mode and enter the base XP gained before the method multiplier.
Why can actual bones used differ?
Some methods include random preservation, and the calculator reports an expected long-run value rather than a guaranteed inventory count.

Last updated 7/17/2026