Pet Medication Unit Converter
Convert a dose your vet has already prescribed from milligrams into millilitres, or into tablets.
Only ever convert a dose your vet has prescribed
This tool does not decide doses. Never give human medicines such as paracetamol or ibuprofen to a pet – paracetamol can kill a cat in a very small amount. If you think your pet has had too much of anything, ring your vet straight away.
Liquid medicine: mg to ml
Tablets
Liquid dose
0.5 ml
per dose, 2 times a day
- Total liquid for the course
- 7 ml
- As tablets
- half a tablet
- Tablets for the whole course
- 7
Never split capsules, coated tablets or modified-release tablets, and never give human medicines to a pet.
What this tool is for
Your vet gives you a dose in milligrams; the bottle in your hand is marked in millilitres. That gap is where mistakes happen, especially at ten at night with a wriggling cat. This converter bridges it using the concentration printed on the label – nothing more. It never suggests a dose, because the right dose depends on your pet's weight, age, diagnosis, kidney and liver function and everything else they are taking. That is a veterinary decision, every time.
How the conversion works
Volume in millilitres equals the dose in milligrams divided by the concentration in milligrams per millilitre. If your vet prescribed 25 mg and the bottle says 50 mg/ml, that is 25 ÷ 50 = 0.5 ml. If the label gives the strength as, say, 100 mg in 5 ml, divide first: that is 20 mg/ml.
Tablets and splitting
For tablets, divide the prescribed dose by the tablet strength. A 25 mg dose from a 50 mg tablet is half a tablet. Only split tablets that are scored and only when your vet has confirmed it is fine. Never split capsules, coated tablets or modified-release tablets – the coating controls how quickly the drug is absorbed, and breaking it can release the whole dose at once. A pill splitter from the chemist gives far more even halves than a kitchen knife.
Giving medicine safely
- Use the syringe supplied with the medicine – kitchen spoons are not accurate.
- Shake suspensions well; the drug settles and the first ml can be much weaker than the last.
- Check whether it should be given with food; some cause stomach upset on an empty stomach.
- Finish the full course of antibiotics even if your pet seems better.
- Store as directed and keep everything well out of reach of children and animals.
Never give human medicines
It bears repeating. Paracetamol is fatal to cats at doses a person would not notice, ibuprofen causes stomach ulcers and kidney failure in dogs and cats, and many human tablets contain xylitol in the coating, which is dangerous to dogs. Even medicines prescribed for one pet should never be given to another animal in the house.
If something goes wrong
Given a double dose, given the wrong pet's medicine, or found a chewed packet? Ring your vet or your out-of-hours emergency service immediately with the packaging in hand. Do not wait for symptoms and never try to make your pet sick at home.
Frequently asked questions
How do I convert mg to ml for a liquid medicine?
Divide the prescribed dose in milligrams by the concentration in milligrams per millilitre. A 25 mg dose of a 50 mg/ml liquid is 0.5 ml.
Where do I find the concentration?
On the bottle label and the leaflet, written as mg/ml – for example '50 mg/ml' or '100 mg in 5 ml', which is 20 mg/ml.
Can I give my pet human medicines?
No. Paracetamol, ibuprofen and many other human medicines are toxic to dogs and cats, and paracetamol can be fatal to cats in tiny amounts. Only give medicines prescribed for that animal by a vet.
Is it safe to split tablets?
Only if your vet says so and the tablet is scored. Never split capsules, coated tablets or modified-release tablets – splitting these changes how the drug is absorbed.
What if I miss a dose?
Give it when you remember unless the next dose is nearly due, in which case skip it. Never double up. Ring your practice if you are unsure – they would far rather answer the question.
What if I think I have given too much?
Ring your vet immediately, or out of hours your emergency vet. Have the packaging with you. Do not wait for symptoms and do not try to make your pet sick.
Why does this calculator not tell me a dose?
Because working out a dose needs your pet's weight, age, kidney and liver function, other medicines and diagnosis. That is a veterinary decision. This tool only converts a dose your vet has already prescribed.
Estimates only – not a substitute for advice from your vet.
Last reviewed: 22 September 2026