Molten Strike DPS Calculator

Inputs from Path of Building

Do not enter this value. This field is included in the calculator just to emphasize that you should type in the average damage, not the total DPS. The reason for this subtlety is that there have been quite a few bugs in PoB calculating ball attack rates incorrectly. By typing in the damage and melee attack rate, it's easier to ensure the final calculations are correct.

Enter the "Average Damage" not the "Total DPS" for "Magma Balls" from Path of Building.

Note that the Total DPS line in PoB can be highly inaccurate due to a bug in how Multistrike is handled in it, in addition to it ignoring the number of balls, chance of balls to land in range of a boss, how to apply the point blank multiplier correctly, etc. The purpose of this calculator is to compute the true DPS, at least until PoB can be enhanced to do so itself.

%
Enter the "Hit Chance" for "Magma Balls" from Path of Building. This will typically be 85-95% for builds that don't have 100% chance to hit (Champion, Lycosidae, etc.).

Do not enter this value. This field is included in the calculator just to emphasize that you should type in the average damage, not the total DPS. The reason for this subtlety is that there have been quite a few bugs in PoB calculating ball attack rates incorrectly. By typing in the damage and melee attack rate, it's easier to ensure the final calculations are correct.

Enter the "Average Damage" not the "Total DPS" for "Melee Hits" from Path of Building.
Enter the "Attack Rate" for "Melee Hits" from Path of Building. Be sure to select melee hits instead of magma balls, especially if you have melee-only attack speed modifiers (e.g. Multistrike). This is because there's a known collection of bugs in PoB causing it to calculate the attack speed incorrectly when the magma balls are selected.
%
Enter the "Hit Chance" for "Melee Hits" from Path of Building. This will typically be 85-95% for builds that don't have 100% chance to hit (Champion, Lycosidae, etc.).

Tell this calculator how you configured Point Blank in Path of Building's configuration tab. If you check this checkbox and/or any of the Grelwood Shank boxes, this calculator will adjust its estimates to take into account the subtle interactions between point blank and the skill. The primary benefit of this calculator is that it figures out what fraction of the balls will actually hit and what their average effective point blank multiplier will be.

Typically, you should leave the point blank field in PoB's configuration tab blank. This textbox should be empty if and only if it's empty in PoB. The reason to leave it blank in PoB (and thus here) is that PoB computes point blank effects incorrectly. This textbox is included here so that we can undo those incorrect calculations if your damage numbers included them. Then this calculator can proceed with more accurate calculations.

Tell this calculator if you have some source of the Far Shot buff, e.g. the Deadeye ascendancy node or from the Beltimber sword. This increases the damage of balls that hit far away. This is always a (small) DPS increase.

Number of Balls

Any build that uses Molten Strike as its primary skill should use the "Molten Strike Fires 3 Additional Projectiles" enchantment, when you can afford it. This provides a large DPS increase.
Any build that uses Molten Strike as its primary skill should have two Wildfire jewels because of the extra DPS they provide. When socketed appropriately, each jewel grants 2 additional projectiles and 25% increased AoE. The AoE modifier typically lowers the DPS by a slight amount, but this is much more than offset by the additional projectiles.
Check this box if you are using a Grelwood Shank in your main hand. This will add 2 extra projectiles and force Point Blank effects to be active in this calculator.
Check this box if you are using a Grelwood Shank in your off hand. This will add 2 extra projectiles and force Point Blank effects to be active in this calculator.
%
If you are using the Dying Sun flask, check the checkbox and enter your AoE roll. Prior to 3.0, all flasks had a 30% roll. Starting with 3.0, the roll range is 15-25%.
Change this number if you have any other sources of extra balls not accounted for above.

This is the total number of balls per melee attack, ignoring the effects of Ancestral Call.

A Few Subtler Points

  • If you're using Ancestral Call and using the trick where you attack slightly out of range of a boss to get double ball procs, see the "Effective Ancestral Call Damage Multiplier" inputs. In practice, you will always get less than a 2x damage multiplier even with perfect positioning because (a) you'll only get one melee hit (minor) and (b) the first attack's balls won't be centered on the boss, lowering their hit rate and their average point blank multipliers.
  • If you're using Multistrike, each time you use the skill (click your mouse or press your skill button),
    • you'll attack three times,
    • each of the three attacks will get a full set of the balls countered here, and
    • you get one critical strike roll that's shared by all three melee hits and all the balls (not an independent roll for each ball or even for each of the three rolls).

AoE Modifiers

%
The total amount of flask effectiveness your character has on the tree and on gear. This is typically 0 unless you are a Pathfinder, are using the Alchemist cluster near the Witch start area, or have a relatively rare flask effect mod on your gear.
%
This is the amount of increased AoE inherited from any Wildfire jewels configured in the "Number of Balls" section.
%
This is the effective amount of increased AoE from the Dying Sun flask, enhanced by flask effectiveness. If you unchecked "Dying Sun" in the "Number of Balls" section, you'll see 0 here.
If you are using the Increased Area of Effect gem in your Molten Strike links, type in the gem's level and check the checkbox. This will adjust the area that the balls can land in and the radius of those balls.
Check this if you're using the Concentrated Effect gem in your Molten Strike links. This will adjust the area that the balls can land in and the radius of those balls.
Net increased area of effect from all other sources like the Amplify and Blast Radius clusters.

%

This is how much the base area where balls can land is scaled. This corresponds to the blue and purple areas in Molten Strike's arc shown below (not to scale).

Be aware that Molten Strike has a radius-5 dead zone (r1 in the image), and it does not change with any AoE modifiers.

Boss Details

We have limited information about the radius of monsters in PoE, but most humanoid monsters have radius 2 and the maximum object radius in PoE is 5. Be aware that the size of the graphical objects can be very different from the size of a monster used for calculating hits.

If you put a number >1.5 in here, your DPS estimate is BS. Don't do that in build guides.

Experienced users of Molten Strike know that there's a trick you can use to get better single-target DPS with Ancestral Call. You stand just outside of melee range from the boss and force a ground attack. The ground attack will spawn balls. If the boss is within 2x your melee weapon range, then AC will proc a melee hit on the boss and spawn a second set of balls. So you get one melee hit and two sets of balls.

A common mistake is to assume this will double your ball DPS. This is a bad assumption for multiple reasons.

  • The first volley of balls is not centered on the boss, so it will have a lower point blank multiplier than the second volley.
  • Since the first volley isn't centered, it will also have a lower hit rate. This is due to the way ball locations are randomly sampled. For the math geeks, it's uniform over (angle, distance) not uniform over the area.
  • Perfect positioning is extremely hard. unless you really believe you're one of the top 100 most skilled players in the game, you're not going to have anywhere near perfect positioning, and definitely not reliably.
  • A lot of newer bosses move around when you're not in their melee range, so maintaining perfect positioning without interrupting your attacks is often very difficult.

As a reult, if you're reasonably skilled and are trying hard to have great positioning, you'll likely only get a 1.5x multiplier (50% more) by using the Ancestral Call trick.

In most true face-tanking single-target situations with non-moving, you'll get more DPS by swapping AC for another gem. That said, many users will still use AC for bosses. It effectively doubles your melee range, and this is especially helpful against mobile bosses. Most bosses have adds, so AC can proc off them and give a nice DPS boost. AC is great for clearing. It's inconvient to switch gems between clearing and bossing modes.

Damage per Second, etc.

This is the total actual DPS against an isolated single target monster.

If you're not using Ancestral Call, this assumes your melee hit is exactly centered on the boss, i.e. you've namelocked it.

If you're using Ancestral Call, this uses the damage multiplier that you gave. We assume that the second melee hit is centered on the boss. Using a multiplier > 2.0 is simply wrong for isolated bosses. Using a multiplier close to 2.0 is unrealistic: you have to stand back far enough to get a double proc, so the balls from the first melee hit (that only hits the ground) will have balls that are off-center. Also, it's hard to optimize your exact positioning to get the best damage. At this time, we believe 1.5 is a good Ancestral Call multiplier estimate for a skilled player who's trying to optimize their hit placement.

For excruciating detail, see the ipython notebook we used to developing this simplified calculator.


This is the total projectile DPS, accounting for the DPS per projectile, point blank effects, Ancestral Call bonuses, Far Shot, and the hit rate due to AoE effects. See the "Total Isolated Single Target DPS" help string for more details.
This is the total DPS from melee attacks, accounting for your chance to hit, your attack speed, and your average damage per hit.

%

This is your chance to hit an enemy for a single ball, assuming that the melee hit is centered on the boss as it should be if you're namelocking, and taking into account your accurace ("Hit Chance" for magma balls). This does not take into account your melee hit chance and how That interacts with Ancestral Call.

We compute the ratio of the purple area to the purple + blue area to get the chance for a molten strike ball to hit a boss. We need to carefully ignore the pink area in doing this calculation.

%

This is the chance to hit if you had 100% accuracy. See the "Chance to Hit an Enemy Per Ball" box for a more detailed explanation.

This is the average number of balls that will hit the isolated boss for each melee attack, assuming you're namelocking.

If you're using Ancestral Call with the double melee trick, this doesn't account for the extra balls from the initial ground hit (we account for them via the damage multiplier).

Other Detailed Calculations

Radius of zone that the balls fall in. See this Wolfram Alpha page for the derivation.

This is the radius of a magma ball, after accounting for AoE modifiers.

Note: Projectiles and game entities are actually squares, not circles in PoE. This calculator treats them as circles because it makes the math a lot easier. To make more precise estimates, we need to know if the rotation of a projectile and/or boss is random or not. We also need to know if the "radius" refers to half the length of one side of the square (in which case this calculator underestimates DPS) or half the length of the diagonal of the square (in which case this calculator overestimates DPS).

%
This is how much the outer 20-unit radius moved. If there was no deadzone, this would be the square root of the total net aoe area multiplier (ignoring the +1 and -1 operations), but since the deadzone is not affected by any AoE modifiers, the actual formula for this value is a little more complicated.

%

This is the net multiplier we get for accounting for all of the following (when applicable):

  • accuracy (from "Hit Chance" for magma balls),
  • the fraction of balls that land close enough to a boss to count as a hit,
  • the average point blank multiplier of the balls that land close enough to the boss to count as hits,
  • the average far shot multiplier of those balls,
  • Ancestral Call, and
  • the number of balls.

To get the total projectile DPS, compute "Average Damage" * "Attack Rate" * (1 + Total "More" Projectile Damage).

%
This is the net effective "more" multiplier applied to your projectiles from point blank, for namelocked bosses. The maximum value is 50%.
%
This is the net effective "more" multiplier applied to your projectiles from far shot, for namelocked bosses. The multiplier is higher for mobs far away from the melee hit, but this calculator is focused on single-target damage.

Help

Click on a field to see details about it here.

Overview

In Path oF Exile (PoE), the Molten Strike skill provides one of the highest single-target damage options in the game. This damage comes from some complex interactions that are not handled in the in-game tooltip or by tools like Path of Building (PoB). This calculator complements PoB to help users estimate their true single target DPS against isolated single targets.

To use this calculator, enter appropriate inputs in all the editable input fields. For more details on a given input or output, click on its description or data field and this help section will be replaced by details about that line.

This calculator is valid for at least the 2.6 to 3.4 patches of PoE.

Known Limitations

  • This calculator assumes all radii are floating point numbers, but some or all are probably integers in the game. Additional experiments are needed to determine exactly how the rounding works. This implies you shouldn't use this calculator to try minmaxing your AoE.
  • This calculator assumes both bosses and balls have circular hitboxes, but past statements from Mark_GGG suggest that some or all hitboxes are actually squares. Additional experiments are needed to verify this and to determine how square orientations are chose.

Version History

  • 2018-11-01: improved how point blank and farshot multipliers are presented. Also made a few other minor improvements to help strings, internal comments, code clarity, etc. Added a limitations section to the main help string.
  • 2018-10-29: added far shot support
  • 2018-10-28: converted to a Javascript implementation. this version supports bookmarking, has more intuitive inputs that work around PoB bugs, adds more point blank inputs so people don't double-count it, adds an Ancestral input, adds convenient inputs for automating the ball count calculations, lots of documentation, etc.
  • 2018-07-28: added usage notes (thanks xhul for the feedback!)
  • 2017-07-15: fixed projectile spread distribution based based on info tracked down by reddit. Also added a graph for finding the optimal AoE modifier.
  • 2017-05-29: original Google Sheets version

Copyright (C) 2018 by MoldyDwarf, all rights reserved. You are free to use the results of this calculator for your builds and build guides, link to it, etc. OpenARL is free to copy any of these calculations into Path of Building if he so desires, with no restrictions.