Group size estimator

How many trainers do I need to invite?

The Estimator is already "trainers of this attacker needed to finish inside the timer", so this page does not invent a number: it reads it off the boss's own ranked counter list for three realistic parties and re-simulates each of them at every level from 20 to 50.

Raid bossTierIVsWeatherFriendshipDodgingShadow attackersMega attackersLegendary attackers

Invite 4 to be safe — 3 if everyone is prepared

At level 40, a party of Mega Meganium's top six counters needs 2.78 trainers (round up: 3), and a mixed lobby of ranks 13-24 needs 3.70 (round up: 4). The raid timer is 300 seconds and one prepared trainer alone would take 12:57. No level in this range makes it soloable with a prepared party.

Mega Meganium · Mega Legendary

grassfairy

Weak to

poisonflyingsteelfireice

Boss CP: 68,601
Boss HP: 22,500
Raid timer: 300s
Party used: 6

Trainers needed, by attacker level

Scroll sideways for the mixed-lobby column.

Trainers needed to beat Mega Meganium at each attacker level
Attacker level	Six of the best counter	A prepared party	A mixed local group	Prepared solo time	Faints per timer
Level 20	4(3.83)	5(4.46)	6(5.79)	20:44	6.0
Level 25	4(3.14)	4(3.86)	5(4.86)	17:57	6.0
Level 30	3(2.56)	4(3.15)	5(4.24)	14:40	6.0
Level 35	3(2.43)	3(2.94)	4(3.92)	13:41	6.0
Level 40	3(2.35)	3(2.78)	4(3.70)	12:57	6.0
Level 45	3(2.25)	3(2.65)	4(3.54)	12:20	6.0
Level 50	3(2.18)	3(2.59)	4(3.40)	12:01	6.0

Whole trainers in bold, the raw estimator in brackets — 2.04 means two trainers is right on the line and three is comfortable.

Six of the best counter

Every trainer brings six copies of the single best counter — the theoretical floor.

3 trainers at level 40

Eternatus2.35

A prepared party

Each trainer brings the boss's top six counters, powered up and correctly TM'd.

3 trainers at level 40

Eternatus2.35
Zamazenta (Crowned Shield)2.72
Zacian (Crowned Sword)2.80
Roserade2.83
Necrozma (Dusk Mane)2.99
Naganadel3.02

A mixed local group

Ranks 13-24: reasonable but unoptimised parties, which is what a public lobby usually is.

4 trainers at level 40

Overqwil3.48
Salamence3.55
Reshiram3.61
Moltres3.66
Genesect (Douse)3.67
Toxicroak3.69

The party these numbers assume

1. Eternatus

Poison Jab + Sludge Bomb

2. Zamazenta (Crowned Shield)

Metal Claw + Behemoth Bash

3. Zacian (Crowned Sword)

Metal Claw + Behemoth Blade

4. Roserade

Poison Jab + Sludge Bomb

5. Necrozma (Dusk Mane)

Metal Claw + Sunsteel Strike

6. Naganadel

Poison Jab + Sludge Bomb

See the full ranked counter list for Mega Meganium · check a real lobby (win chance, who brings what) · make a share card of the top six

How this is worked out

The boss is ranked once at level 40 with rankCached (the same memoised call /raids makes), then the three bands — rank 1, ranks 1-6, ranks 13-24 — are re-simulated at each attacker level with an 8-run Monte Carlo each. Holding the party fixed and moving only its level is deliberate: it answers "what if my party were level 20" rather than "what would a level-20 player's completely different party be", and it is about ten times cheaper than re-ranking every attacker seven times. The Estimator itself is Pokebattler's definition, time to win including rejoin time divided by the raid timer.