ATP Yield Calculator – Cellular Respiration

Calculate ATP yield from complete oxidation of glucose, fatty acids, or amino acids.

Substrate

Custom NADH count

Custom FADH₂ count

Custom GTP/ATP count

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Worked Examples

Example 1: Complete glucose oxidation

Glycolysis + PDH + TCA + ETC

Result: ~30-32 ATP per glucose

Using P/O ratios of 2.5 (NADH) and 1.5 (FADH₂)

Example 2: Palmitate (C16:0 fatty acid)

7 rounds β-oxidation + 8 acetyl-CoA

Result: ~106 ATP per palmitate

Fat yields more ATP/gram than carbohydrate

Frequently Asked Questions

Why does fat yield more ATP than glucose?

Fatty acids are more reduced (more C-H bonds) than carbohydrates. Palmitate (16C) yields ~106 ATP vs 32 ATP for glucose (6C). Per gram: fat ≈ 9 kcal; carbohydrate ≈ 4 kcal.

Why 30-32 ATP, not the old textbook 36-38?

Modern P/O ratios: NADH → 2.5 ATP; FADH₂ → 1.5 ATP (not 3 and 2 as in older texts). These reflect actual measured values from chemiosmotic coupling efficiency.