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Dog chocolate toxicity calculator
Your dog ate chocolate? Enter their weight, the type of chocolate and how much they ate to see how serious it is and what to do next.
The dose your dog ate, how serious it is and what to do next will show here.
This calculator helps you judge urgency. It does not replace a vet. If your dog is showing any signs, go to a vet now. Last reviewed October 6, 2026.
How this calculator works
Chocolate is toxic to dogs because of two stimulants it contains, theobromine and caffeine, together called methylxanthines. Dogs break them down much more slowly than people do, so a small amount can build up to a harmful dose.
The calculator multiplies the amount eaten by the methylxanthine content of that type of chocolate, then divides by your dog's weight. The result is a dose in milligrams per kilogram of body weight (mg/kg), which vets use to judge how serious the exposure is. The content values and dose thresholds come from the Merck Veterinary Manual's chapter on chocolate toxicosis, last updated in February 2026.
What the dose means
| Dose | What can happen | What to do |
|---|---|---|
| Under 20 mg/kg | Signs are uncommon, though fat and sugar can still upset the stomach | Watch closely for 12 hours; call your vet if unsure |
| 20 mg/kg and up | Vomiting, diarrhea, increased thirst | Call your vet now |
| 40–50 mg/kg and up | Fast or irregular heartbeat, restlessness, tremors | Go to a vet now |
| 60 mg/kg and up | Seizures; can be life-threatening | Emergency vet immediately |
Dogs differ in how sensitive they are, and severe signs can happen below these levels. For milk chocolate, about 1 ounce per pound of body weight is a potentially lethal amount.
How much theobromine and caffeine is in chocolate
| Type | mg per oz | mg per gram |
|---|---|---|
| Dry cocoa powder | 807 | 28.5 |
| Unsweetened baking chocolate | 440 | 15.5 |
| Cocoa bean hulls (mulch) | 255 | 9 |
| Semisweet and sweet dark chocolate | 150–160 | 5.3–5.6 |
| Milk chocolate | 64 | 2.3 |
| White chocolate | 1.1 | 0.04 |
For dark chocolate with a cocoa percentage on the label, the calculator scales the baking chocolate value: a 70% bar has about 70% of 15.5 mg, or 10.9 mg per gram. For semisweet and dark chocolate without a percentage, it uses the higher end of the range to stay on the safe side. Some cocoa mulches have had the methylxanthines removed; if you don't know, assume they haven't.
Two examples
- A 20 lb (9.1 kg) dog eats a 1.55 oz (44 g) milk chocolate bar: 44 g × 2.3 mg = 101 mg, or about 11 mg/kg. That's below the level where signs are usually reported, but the dog should still be watched.
- The same dog eats 1.5 oz (42.5 g) of 70% dark chocolate: 42.5 g × 10.9 mg = 461 mg, or about 51 mg/kg. That's in the range where heart effects are possible, and the dog should see a vet now.
Signs of chocolate poisoning usually start 6 to 12 hours after eating and can last up to 3 days in severe cases. Vets can often prevent signs if they treat early, so call before your dog seems sick. Don't try to make your dog vomit at home unless a vet tells you to.
Questions people ask
How much chocolate is toxic to a dog?
Mild signs can start at about 20 mg of theobromine and caffeine per kilogram of body weight, heart effects at 40 to 50 mg/kg, and seizures at 60 mg/kg or more. How much chocolate that takes depends on the type: a dog needs to eat far less cocoa powder or baking chocolate than milk chocolate to reach the same dose.
Which chocolate is most dangerous for dogs?
The darker and less sweet, the more dangerous. Dry cocoa powder and unsweetened baking chocolate contain the most theobromine, followed by dark and semisweet chocolate. Milk chocolate has much less, and white chocolate has almost none.
How long after eating chocolate will a dog show signs?
Usually within 6 to 12 hours. Early signs include vomiting, diarrhea, increased thirst and restlessness. In severe cases signs can last up to 72 hours.
What should I do if my dog ate chocolate?
Work out the type and amount, enter it above, and call your vet or a pet poison line with the result. Keep the wrapper. Don't give food, milk or home remedies, and don't make your dog vomit unless a vet tells you to.
Is white chocolate safe for dogs?
White chocolate contains almost no theobromine, so poisoning is very unlikely. It is still high in fat and sugar, which can cause vomiting, diarrhea or pancreatitis, especially in small dogs that eat a lot of it.
Can cats get chocolate poisoning too?
Yes. Many animals are sensitive to theobromine. Cats are poisoned less often because they rarely eat sweets. This calculator is built for dogs, so if your cat ate chocolate, call your vet.