40 CARROTDefine the required game effect
Write the minimum result that makes the play worthwhile, such as removing one model, clearing a unit, or opening a lane.
Mathhammer guide
11th Edition|
Updated 30 Jul 2026|
Verified against the live calculator|
8 min read
How do you use 40K damage probability to make better trades?
Damage math becomes useful when it answers a game question. Define the result you need, read the range honestly, and judge the position that remains when the dice fall low.
TL;DR
Define what the play must accomplish, enter the real profiles and supported modifiers, and read average damage, models destroyed, wipe probability, and the kill distribution as a range rather than a promise. Then price the whole exchange: the scoring need, the cost of failure, and the opponent’s likely return trade.
What is the difference between a result and a decision?
A damage roll tells you what happened once. Probability helps you judge whether taking that line was reasonable before the dice. A sound attack can roll low, and a poor attack can spike.
Start with the mission effect. Do you need to remove one model to reduce Objective Control, clear the whole unit to open a charge lane, bracket a vehicle, or force a defensive resource? The calculator has no custom success-threshold control, so compare its outputs with the requirement you wrote.
Use the calculator in four passes
Hold the mission requirement still while you compare attack plans.
Enter and verify the profiles
Enter the real attacker, defender, weapons, model counts, and supported modifiers, then check every displayed assumption.
Read the whole distribution
Compare average damage and models destroyed with wipe probability and the spread of likely kill counts.
Price the return trade
Add the scoring swing, exposure, follow-up activations, and the opponent’s likely answer before choosing the line.
Measure the exchange before you calculate it
The free Damage Calculator works without an account. Enter profiles directly, use a saved calculator loadout, choose a recent unit-name shortcut, or send selected models from the Virtual Tabletop. Attackers selected on the table use their live weapon data. Always verify model count, stats, weapons, and modifiers.
Write the decision before reading the result
This short check keeps one high average from hiding a fragile plan.
Trade decision template
- Need
- Remove enough models to take the objective this turn.
- Range
- Record average damage, average models destroyed, wipe chance, and likely kill counts.
- Failure
- The attacker is exposed and the objective remains contested.
- Return
- Name the enemy unit that can answer and the score or material it can recover.
How do you read the output without treating it as a promise?
- Average damage is the long-run center, not the most important outcome in every position.
- Average models destroyed translates damage into the defender’s wound and model profile.
- Wipe probability shows how often the attack clears the full defender under the entered assumptions.
- Kill distribution exposes how often each model-loss result occurs and whether the range is wide or narrow.
The searchable name picker does not supply official weapon or stat profiles. The unit lookup elsewhere in 40 Carrot provides names, base sizes, and current official points, not complete datasheets.
How do you price the whole trade?
Add the movement and scoring consequences around the attack. Which unit must leave cover? What objective changes hands? Does a second activation become available if the first falls short? Which enemy unit can answer? A better damage number can still be a worse trade if the attacker gives up more score or material.
Keep the defender and mission requirement fixed. Change one choice at a time: target, weapon split, supported modifier, or participating unit. After the dice, ask whether the result sat inside the plausible range and whether your decision accounted for the lower end. Use the game review method to test the alternative without changing everything else.
Check the trade before you commit
Open the calculator →The Damage Calculator is free and works without an account.
Frequently asked questions
What does 40K damage probability tell me?
With the profiles and supported modifiers you enter, 40 Carrot calculates average damage, average models destroyed, wipe probability, and the kill distribution. Those outputs describe a range of possible results. They do not choose the target, price the return trade, or guarantee an outcome.
Is the 40 Carrot Damage Calculator free?
Yes. The Damage Calculator is free and works without an account. You can enter profiles directly on its public page. Inside the Virtual Tabletop, you can also send selected models on the table to the calculator and use live attacker weapon data.
Why is average damage not enough?
An average hides how often low and high results occur. Read the kill distribution and wipe probability beside the average, then compare them with what the play needs to accomplish. A line can have a strong average and still fail too often for the mission situation.
Does the calculator include every 40K rule and modifier?
No. It supports the modifiers listed in the calculator, but it does not know every rule interaction. Enter the current profiles and applicable effects, check the displayed hit, wound, and save assumptions, and use current official rules to resolve anything the calculator does not model.
Does the unit picker supply official weapon and stat profiles?
No. The searchable picker is a name and model-count shortcut, not a source of official profiles. Use a saved calculator loadout, a recent unit-name choice, or models selected on the table, then verify or enter the real stats, weapons, and supported modifiers yourself.