5E Chance To Hit Calculator

Estimate your odds to land an attack in Dungeons and Dragons 5e with normal rolls, advantage, or disadvantage. Enter your attack bonus, the target armor class, and optional critical range to see hit chance, miss chance, and critical hit probability instantly.

Expert Guide to the 5e Chance to Hit Calculator

A 5e chance to hit calculator helps players and Dungeon Masters answer one of the most practical questions in combat: how likely is an attack to connect? In Dungeons and Dragons 5th Edition, attack resolution looks simple on the surface. You roll a d20, add your attack bonus, and compare the total to the target’s Armor Class. If the roll meets or beats that AC, the attack hits. However, actual outcomes become more interesting once you include natural 1s, natural 20s, advantage, disadvantage, and expanded critical ranges from class features such as the Champion Fighter. This calculator puts those factors together into a fast, visual decision tool.

At a strategic level, hit probability matters because it shapes nearly every turn. It affects whether Sharpshooter or Great Weapon Master is worth activating, whether Bless provides more expected value than a direct damage effect, how dangerous a high AC monster really is, and how often a rogue can expect Sneak Attack to land. Even if your table plays casually, understanding hit rates improves tactical choices, encounter design, and expectations for how often abilities will actually pay off in play.

How 5e attack rolls work

The baseline formula is straightforward:

Attack Roll = d20 + attack bonus

If that total equals or exceeds the target’s Armor Class, the attack hits. There are two important exceptions built into the core rule engine:

• A natural 1 on the d20 is an automatic miss.
• A natural 20 on the d20 is an automatic hit and also a critical hit.

Those rules create a floor and a ceiling on hit probability. No matter how high your attack bonus becomes, you still miss on a natural 1. No matter how poor your bonus is, you always have at least a chance to hit on a natural 20. That means ordinary attack rolls on a single d20 usually fall between 5% and 95% total hit chance.

What this calculator measures

This calculator returns four practical values:

1. Total hit chance: the percentage of attack outcomes that land.
2. Non-critical hit chance: the percentage of hits that are regular hits.
3. Critical hit chance: the percentage of outcomes that crit.
4. Miss chance: the percentage of attack outcomes that fail.

It also plots a chart showing how your current attack setup performs against many AC values. That chart is useful because combat planning is rarely about one exact target. You may be evaluating a build against common enemy defenses across a campaign, or deciding whether a buff is worth using against low, medium, or high AC foes.

Why advantage and disadvantage matter so much

Advantage and disadvantage are among the most powerful mechanics in 5e because they change the shape of the probability curve rather than just adding a flat modifier. With advantage, you roll two d20s and keep the higher result. With disadvantage, you roll two d20s and keep the lower result. That creates a dramatic swing in outcomes, especially when your baseline chance to hit is in the middle range.

For example, suppose you need a roll of 11 or better on a d20 to hit after modifiers. On a normal roll, that is a 50% chance. With advantage, the chance jumps to 75%. With disadvantage, it falls to 25%. The reason is simple: advantage reduces the chance that both dice are bad, while disadvantage reduces the chance that both dice are good.

Needed d20 Result	Normal Hit Chance	Advantage Hit Chance	Disadvantage Hit Chance
6+	75%	93.75%	56.25%
8+	65%	87.75%	42.25%
11+	50%	75%	25%
14+	35%	57.75%	12.25%
16+	25%	43.75%	6.25%

These are real probabilities based on the distribution of two twenty-sided dice. Notice that advantage is especially valuable when you are not already near the 5% or 95% edges. That is why mechanics that grant advantage, such as reckless attacks, restraining a target, being unseen, or a familiar using the Help action, can be so influential in actual play.

Using attack bonus and AC to estimate your odds

One fast way to think about hit chance is to compare your attack bonus against the target’s AC. If your attack bonus is +7 and the enemy AC is 16, you need a 9 on the d20 because 9 + 7 = 16. On a normal roll, that means results 9 through 20 hit, except that the natural 1 rule would already be irrelevant in this case because 1 would not have hit anyway. The hit rate becomes 12 successful results out of 20, or 60%.

Here is a practical comparison table using common 5e values:

Attack Bonus	AC 13	AC 15	AC 17	AC 19
+5	65%	55%	45%	35%
+7	75%	65%	55%	45%
+9	85%	75%	65%	55%
+11	95%	85%	75%	65%

Each +1 bonus is worth roughly 5 percentage points on a single d20 roll, provided you are not already capped by the natural 1 and natural 20 rules. That is one of the most useful heuristics in 5e optimization. If a feature gives +2 to hit, it often changes your hit rate by about 10 percentage points. Over multiple attacks, that can outperform options that add damage but lower accuracy.

Critical range and why it changes expected outcomes

Most characters score a critical hit only on a natural 20, which means a 5% crit rate on a normal attack. Some features expand that range. A Champion Fighter can crit on a 19 or 20, and later on an 18 to 20. Expanded critical range does not simply increase burst damage. It also changes expected DPR because a larger slice of your successful attacks become critical hits. With advantage, the effect becomes much stronger because your chance to see at least one die in the critical range increases sharply.

For example, with a standard 20-only crit range:

• Normal crit chance: 5%
• Advantage crit chance: 9.75%
• Disadvantage crit chance: 0.25%

With a 19 to 20 crit range, those numbers become:

• Normal crit chance: 10%
• Advantage crit chance: 19%
• Disadvantage crit chance: 1%

Those are large shifts in output. If your build adds many extra damage dice on a hit, critical frequency becomes more valuable than it first appears.

When a calculator is better than mental math

Mental shortcuts are great for quick table decisions, but a dedicated calculator becomes more useful as conditions stack up. Imagine a character with +8 to hit attacking AC 18 under advantage and critting on 19 to 20. Calculating total hit rate, non-crit hit rate, and crit rate in your head is possible, but not efficient in the middle of play. A reliable calculator saves time and avoids common mistakes, especially with advantage and custom crit thresholds.

This matters most when making comparative decisions such as:

• Should I use Sharpshooter or Great Weapon Master this round?
• Is it better to attack at disadvantage now or reposition first?
• How much does Bless improve my odds against high AC targets?
• Does a +1 weapon outperform a situational damage booster over time?
• How threatening is a monster’s AC to the current party lineup?

Interpreting your results in real play

Players often overestimate how often they hit and underestimate how much advantage helps. A 60% hit rate means you still miss 2 out of every 5 attempts on average. Conversely, moving from 60% to 70% does not sound dramatic, but across a long combat or a whole campaign that increase is enormous. It raises consistency, improves resource conversion, and makes riders that trigger on hit much more dependable.

As a practical rule:

1. Below 50%, attack penalties become very expensive.
2. Between 55% and 70%, accuracy boosts are often premium value.
3. Above 75%, damage riders become more appealing because your baseline connection rate is already strong.
4. Advantage is often worth more than a small flat bonus, especially around the middle of the curve.

Useful probability references

If you want to understand the math behind hit chance more deeply, these probability resources are excellent starting points:

• NIST Engineering Statistics Handbook
• Probability overview from a college-level statistics text
• U.S. Department of Education probability primer

Common mistakes players make

The most frequent mistake is ignoring the automatic miss and automatic hit rules. Another is treating advantage as if it were a flat +5. While advantage can sometimes feel similar to a sizable bonus, it is not constant across all target numbers. A third common mistake is forgetting that under disadvantage, a natural 20 on one die does not help if the lower die is not also a success. The selected die is what matters.

Players also sometimes focus too much on peak damage outcomes. In actual campaign play, consistency usually wins. A build that hits more often contributes steadier damage, lands control riders more reliably, and wastes fewer resources. That is one reason calculators like this are useful for evaluating feats, fighting styles, class features, and spell support.

How to use this calculator effectively

Start with your current attack bonus and the AC you expect most often. Then compare three scenarios: normal, advantage, and disadvantage. After that, adjust the AC by one or two points in either direction to see how sensitive your build is to enemy defenses. Finally, if your character has expanded critical range, compare the impact with and without advantage to understand how often your build can capitalize on crit-based damage spikes.

For Dungeon Masters, this same tool helps tune encounters. If the party’s frontliners only have a 40% chance to hit your boss, combat may feel frustrating unless the creature’s lower HP or tactical vulnerabilities compensate. If the party is landing at 80% or more while also stacking advantage, a so-called tough enemy may collapse faster than expected.

Bottom line

A 5e chance to hit calculator is more than a novelty. It is a practical way to translate game rules into informed tactical decisions. Because 5e combat is built around bounded accuracy, small bonuses matter, and advantage matters even more. By calculating total hit rate, critical chance, and miss chance at a glance, you can make smarter choices about positioning, buffs, feats, and target selection. Use the calculator above whenever you want a cleaner read on your odds before committing to an attack plan.