Eternal Calculus
For the Path of: EruditionEternal Calculus is a 5★ Light Cone for the Path of Erudition in Honkai: Star Rail.
A 5-star Mage cone that grants solid base ATK plus stacking ATK per enemy hit (up to 5 stacks) and a SPD boost against 3+ targets, making it near-optimal for sustained DoT/AoE damage teams, earning SS tier.
Eternal Calculus is a Light Cone for the Erudition Path. Ranked SS on the Light Cone tier list. Best paired with Rappa. Needs 7 material types to reach Lv.80.
Last updated: 31/07/2026
The figures on this page come directly from gamevika's internal game data store (counted/read straight from the real records), not an estimate or copy from elsewhere.
Effect
Increases the wearer's ATK by 8%. After using an attack, for each enemy target hit, additionally increases ATK by 4%. This effect can stack up to 5 times and last until the next attack. If there are 3 or more enemy targets hit, this unit's SPD increases by 8%, lasting for 1 turn(s).
Is Superimposition S1 → S5 worth it?
Base Stats (Lv80)
| Lv. | HP | ATK | DEF |
|---|---|---|---|
| 1 | 48 | 24 | 18 |
| 20 | 185 | 92 | 69 |
| 30 | 178 | 89 | 67 |
| 40 | 254 | 127 | 95 |
| 50 | 331 | 166 | 124 |
| 60 | 408 | 204 | 153 |
| 70 | 485 | 242 | 182 |
| 80 | 562 | 281 | 211 |
Best Characters
A solid build option for Rappa (not the #1 pick, but still in the recommended group).
Ascension Materials
Characters who use this
Story
Eternally suspended in the void, Streams of shimmering data flood into THEIR mind. Turning all things past and future into symbols, THEY deduce the end from the beginning. Knowledge, answers, truths... In the mist of information, a brilliant light arises, And everything becomes clear to THEM.
Alternative cones on the same Path
Trivia & Origins
HoYoverse's own game data has no gacha table pairing this cone with a specific character, and the internal flavor text doesn't name one either — not enough evidence to assign a signature owner, no guessing.
Frequently Asked Questions
What does Eternal Calculus do?
Increases the wearer's ATK by 8%. After using an attack, for each enemy target hit, additionally increases ATK by 4%. This effect can stack up to 5 times and last until the next attack. If there are 3 or more enemy targets hit, this unit's SPD increases by 8%, lasting for 1 turn(s).
What does Eternal Calculus do at Superimposition 5 (S5)?
Increases the wearer's ATK by 12%. After using an attack, for each enemy target hit, additionally increases ATK by 8%. This effect can stack up to 5 times and last until the next attack. If there are 3 or more enemy targets hit, this unit's SPD increases by 16%, lasting for 1 turn(s).
Who should use Eternal Calculus?
Based on cross-source consensus builds, this cone works best on: Rappa, Jade.
How many materials does it take to ascend Eternal Calculus to Lv.80?
You need 7 material types and 385,000 Credits to ascend the cone to Lv.80 (see the table above for details).
How to read this Light Cone page
Every Light Cone has exactly one passive effect tied to the wielder's combat performance; that effect scales up as you Superimpose it from S1 to S5 — use the S1-S5 buttons above to see the exact numbers at each level instead of guessing or interpolating. A Light Cone only delivers its full value on a character who shares its Path; "Characters who use this cone" lists every character on that Path, while "Best users" is a narrower list pulled from real build consensus, not a guess.
Base stats (HP/ATK/DEF) are shown at Lv80 for every cone of the same rarity so they can be compared directly; a 5-star cone will always edge out 4-star and 3-star ones here — the real difference lives in the passive effect, not the flat stats. The "Alternative cones on the same Path" section suggests a few other options if you do not own the signature cone yet, or want to compare before spending ascension materials.
See the full list on the Light Cones page, or check terms in the HSR Glossary.
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