Chocolate Toxicity Calculator
The danger is the theobromine in cocoa, and the dose depends on your dog's weight and the type of chocolate. Enter all three and see which zone you are in: low, mild signs possible, or head to the vet now.
Thresholds from the Merck Veterinary Manual: mild signs possible from 20 mg/kg, heart effects from 40 to 50, seizures from 60. The calculator is not a diagnosis.
The formula we use
methylxanthine mg = grams x concentration (milk 2.3 · dark 5.6 · baking 15.5 · cocoa 28.5) · dose = mg / kg of body weight The toxic compounds are theobromine and caffeine, two methylxanthines that dogs clear very slowly. Concentrations follow the Merck Veterinary Manual (updated February 2026), which counts both together. Ounces and pounds are converted to grams and kilograms before the math. The concentrations and dose thresholds come from the veterinary literature and are listed on the Methodology page. Dark chocolate is more than twice as dangerous as milk chocolate, and cocoa powder is about twelve times more concentrated.
Guides for the next few hours
How much chocolate is dangerous, by dog weight
Signs a dog ate chocolate, hour by hour
My dog ate chocolate but is acting fine
Dog ate a chocolate chip cookie
Can cats eat chocolate?
After the scare is over
Stolen snacks and counter surfing count toward daily calories. Check what your dog should actually be eating with the dog food calculator →
Frequently asked questions
How much chocolate is dangerous for a dog?
It depends on your dog's weight and the type of chocolate. The dangerous compounds are theobromine and, to a lesser degree, caffeine. Together, milk chocolate has about 2.3 mg per gram, dark and semi-sweet about 5.6, unsweetened baking chocolate about 15.5, and cocoa powder a full 28.5. The Merck Veterinary Manual reports mild signs from 20 mg per kg of body weight, heart effects from 40 to 50 mg/kg and seizures from 60 mg/kg. For a 20 lb dog, barely half an ounce of cocoa powder already crosses into the danger zone.
What are the symptoms of chocolate poisoning?
The first signs appear 6 to 12 hours after ingestion: vomiting, diarrhea, heavy thirst, restlessness. At higher doses: racing heart, trembling, stumbling, seizures. Symptoms can last up to 72 hours because dogs break theobromine down very slowly.
When should I go to the vet immediately?
Immediately if the dose lands in the yellow or red zone of the calculator, if your dog already shows symptoms, or if it is a puppy, a senior, or has a heart condition. Soon after eating, a vet may be able to make your dog vomit up the chocolate before more of it is absorbed. You can also call the ASPCA Animal Poison Control Center at (888) 426-4435 (a fee may apply). One unnecessary call beats one late one.
Is white chocolate dangerous?
White chocolate contains almost no theobromine or caffeine (about 0.04 mg per gram) and carries no real poisoning risk from them. Its heavy fat and sugar load can still cause an upset stomach or pancreatitis, so it is not for dogs either.