How the calculator works
Chocolate contains theobromine and caffeine (methylxanthines). The Merck Veterinary Manual lists how much each type contains per gram, from 0.04 mg in white chocolate to 28.5 mg in dry cocoa powder. For dark chocolate, the calculator scales unsweetened chocolate's 15.5 mg/g by the cacao percentage, the method Merck describes. The total is divided by your dog's weight in kg.
What the ranges mean
According to Merck, mild signs such as vomiting, diarrhea and thirst can occur from about 20 mg/kg. Heart effects appear at 40-50 mg/kg, and seizures at 60 mg/kg or more. Dogs vary, so a dose below 20 mg/kg doesn't make it safe, and a vet call is always the right move.
Methylxanthines by chocolate type
| Chocolate | mg per gram | mg per ounce | Ounces that reach 20 mg/kg in a 20 lb dog |
|---|---|---|---|
| White chocolate | 0.04 | 1 | Not a realistic amount |
| Milk chocolate | 2.3 | 65 | 2.8 oz |
| Semisweet or sweet dark | 5.5 | 156 | 1.2 oz |
| Unsweetened baking chocolate | 15.5 | 439 | 0.4 oz |
| Dry cocoa powder | 28.5 | 808 | 0.2 oz |
Other things to tell your vet
Wrappers and foil can cause blockages. Some chocolate products contain xylitol, raisins or macadamia nuts, which are dangerous to dogs on their own. Fatty chocolate can also trigger pancreatitis a day or two later. Have the packaging ready when you call.
Questions
How much chocolate is toxic for a dog?
Mild signs can start at about 20 mg of theobromine and caffeine per kg of body weight. For a 20 lb dog, that's about 2.8 oz of milk chocolate or less than half an ounce of baking chocolate.
Can I make my dog vomit at home?
Don't try without talking to a vet or poison control first. Home methods can be dangerous, and in some cases making a dog vomit isn't the right treatment.
Is white chocolate safe?
It has almost no theobromine, but it's high in fat and sugar, which can upset a dog's stomach or cause pancreatitis.
Last reviewed October 20, 2026. Estimates for healthy pets only, not veterinary advice.