How OSRS Prayer XP Calc Works
To use the OSRS Prayer XP Calc, enter your Prayer level or exact XP, a target level, a bone, a training method and a bone price, then read the bones and gold needed.
- Enter your current Prayer level and, if you know it, your exact Prayer XP.
- Enter your target Prayer level.
- Pick bones (4.5 XP), big bones (15 XP) or dragon bones (72 XP).
- Pick burying (1×), the gilded altar (3.5×), the Ectofuntus (4×) or the Chaos altar (7× average).
- Enter your price per bone and read the bones and cost.
OSRS Prayer XP Calc Formula
The OSRS Prayer XP Calc formula is Bones = ⌈Prayer XP remaining ÷ (base bone XP × method multiplier)⌉.
Prayer XP remaining = XP at target level − current XP
XP per bone = base bone XP × method multiplier
Bones = ⌈Prayer XP remaining ÷ XP per bone⌉
Cost = bones × price per bone
- Burying gives 1× base XP.
- The gilded altar with 2 lit burners gives 3.5× base XP.
- The Ectofuntus gives 4× base XP.
- The Chaos altar gives 3.5× per offering with a 50% chance to keep the bone, so 7× on average per bone used.
OSRS Prayer XP Calc FAQ
How many dragon bones do I need for 99 Prayer?
You need about 51,700 dragon bones for 99 Prayer from level 1 on a gilded altar, at 252 XP per bone.
How much XP does a dragon bone give on a gilded altar?
A dragon bone gives 252 Prayer XP on a gilded altar with 2 lit burners, which is 3.5 × 72 XP.
Why is the Chaos altar shown as 7×?
The Chaos altar is shown as 7×: each offering gives 3.5× XP and keeps the bone half the time, which doubles the XP per bone used on average.
Is the Chaos altar safe?
No, the Chaos altar is not safe. The altar sits in level 38 Wilderness, where other players attack and kill you for your bones.