Here's a clear, practical guide to calculating HP in D&D 5e — plus a simple way to think about it like a calculator.

The Basic Formula

At 1st level: Hit Points = Maximum of your class's Hit Die + your Constitution modifier

From 2nd level onward you have two choices every time you level up:

1. Roll your Hit Die and add your Constitution modifier
2. Take the average (the fixed value listed in the Player's Handbook) + Constitution modifier

Most tables strongly recommend taking the average for reliability, especially at higher levels.

Hit Dice by Class

Constitution modifier is added every single level (including 1st).

Quick Example

You're building a Fighter 5 / Rogue 3 with Constitution 16 (+3).

• Fighter 1: 10 + 3 = 13
• Fighter 2–5: 4 × (6 + 3) = 36
• Rogue 1–3: 3 × (5 + 3) = 24

Total HP = 13 + 36 + 24 = 73

That's the standard “take the average” method most players and DMs prefer.

Extra Rules Worth Knowing

• Tough feat : +2 HP per level (including levels you already have).
• Draconic Resilience (Dragonborn sorcerer) or similar features: sometimes change your Hit Die or give bonus HP.
• Multiclassing : Always use the Hit Die of the class you just took a level in.
• Temporary Hit Points : These sit on top of your normal HP and don't stack with each other in most cases.
• Maximum HP increases : From leveling, the Tough feat, or certain magic items/spells.

Simple Mental Calculator

You can treat it like this:

text

Starting HP = Class Hit Die max + Con modThen for every level after 1st:  + Average of that class’s Hit Die + Con mod+ Any flat bonuses (Tough, etc.)

Or if you prefer rolling:

text

Starting HP = Class Hit Die max + Con modThen for every level after 1st:  + (1dX + Con mod)

Why Accurate HP Matters

Underestimating your HP can make combat feel brutal. Overestimating it (or forgetting Constitution increases) can make the game less tense than it should be. A clean calculation also helps when you're planning multiclass combinations or deciding whether the Tough feat is worth taking.

Next time you level up, just plug the numbers into the formula above and you'll have the correct total in seconds.

Happy adventuring — and may your hit points stay high!