How to Calculate Passer Rating

Calculating passer rating by hand is straightforward once you understand the components. Here’s a complete step-by-step guide for both the NFL and NCAA formulas.

NFL Passer Rating: Step-by-Step

What you need: Completions (C), Attempts (A), Yards (Y), Touchdowns (T), Interceptions (I)

Step 1: Calculate four raw components:

a = ((C / A) − 0.3) × 5
b = ((Y / A) − 3) × 0.25
c = (T / A) × 20
d = 2.375 − ((I / A) × 25)

Step 2: Clamp each component between 0 and 2.375

If any value is less than 0, set it to 0
If any value exceeds 2.375, set it to 2.375

Step 3: Combine with the final formula:

Rating = ((a + b + c + d) / 6) × 100

Worked Example

Given: 25 completions, 35 attempts, 310 yards, 3 TDs, 1 INT

Component	Formula	Result	Clamped
a	(25/35 − 0.3) × 5	2.071	2.071
b	(310/35 − 3) × 0.25	1.464	1.464
c	(3/35) × 20	1.714	1.714
d	2.375 − (1/35 × 25)	1.661	1.661

Rating = ((2.071 + 1.464 + 1.714 + 1.661) / 6) × 100 = 115.2

NCAA Formula

The college calculation is simpler — just one step:

Rating = (8.4 × Y + 330 × T + 100 × C − 200 × I) / A

Same example: (8.4 × 310 + 330 × 3 + 100 × 25 − 200 × 1) / 35 = 172.9

Quick Tips

Always check that attempts is greater than zero
Remember to clamp NFL components — this is the most commonly missed step
Completions can never exceed attempts
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