Feeding a dog sounds straightforward. It isn't. The guidelines on the back of a food bag are a starting point — nothing more. They're designed for the average dog of that weight, but your dog is not average. Their metabolism, activity level, age, breed and whether they're neutered all affect how much they actually need.
Here's how to think about it properly.
Why bag guidelines are not the final answer
Pet food manufacturers have a commercial incentive to suggest feeding amounts on the higher end. More food consumed means more food purchased. This doesn't mean they're deliberately misleading you — the guidelines are based on real data — but they don't account for the enormous variation between individual dogs.
A highly active Border Collie and a sedentary Basset Hound of the same weight have very different caloric needs. A neutered dog typically needs around 20–30% fewer calories than an intact dog of the same size. An older dog needs less than a young adult. The bag doesn't know any of this about your dog.
Log every meal, monitor appetite trends and track water intake alongside meals to build a clear picture of your dog's eating habits over time.
Body condition score — the most reliable method
The best way to tell if your dog is eating the right amount is not a chart — it's your hands. Vets use a body condition score (BCS) scale from 1 to 9, where 1 is severely underweight and 9 is obese. The target for most dogs is 4–5.
🖐️ The rib check — do this now
- Place both thumbs on your dog's spine and spread your fingers across their ribcage
- Apply light pressure — you should feel the ribs easily without pressing hard
- You should not be able to see the ribs but you should feel them easily
- Look at your dog from above — there should be a visible waist behind the ribs
- Look from the side — the belly should tuck up slightly behind the ribcage
If you can't feel the ribs at all without firm pressure, your dog is likely overweight and their portions should be reduced. If the ribs are very prominent with no fat covering, they may be underweight.
Factors that affect how much your dog needs
Age
Puppies need significantly more calories per kilogram of body weight than adult dogs because they're growing rapidly. Most puppy foods account for this — always feed a puppy-specific food until they reach adult size. Senior dogs typically need fewer calories as their metabolism slows and activity decreases.
Activity level
A working dog, a dog who runs with you daily or a dog who is training intensively needs considerably more food than a dog who does two 20-minute walks a day. If your dog's exercise level changes significantly, their food should too.
Neutering
Neutered dogs have a lower metabolic rate. If your dog was neutered as an adult, it's worth reducing their daily portion slightly after the procedure and monitoring their weight over the following weeks. Many dogs gain weight after neutering simply because their caloric needs dropped and nobody adjusted their food.
Treats
This is where most owners unknowingly overfeed. Treats are calories. If you're using treats for training, which you should be, those calories count. A good rule of thumb is that treats should make up no more than 10% of your dog's daily caloric intake. On high-treat days, reduce the main meal slightly.
Over 50% of dogs in the UK are estimated to be overweight. Excess weight contributes to joint problems, heart disease, diabetes and a significantly shortened lifespan. Getting portions right is one of the most important things you can do for your dog's long-term health.
How often should you feed them?
Most adult dogs do well with two meals a day — morning and evening. This is preferable to one large meal, which can contribute to bloat in larger breeds. Puppies generally need three to four smaller meals a day until around six months of age.
Consistency matters. Try to feed at the same times each day. Dogs thrive on routine and predictable meal times can also help with house training in puppies.
A practical starting point
Start with the lower end of the bag guidelines. Weigh the food with scales rather than using a cup — it's far more accurate. Feed that amount for two to three weeks and do the rib check. Adjust by 10% up or down based on what you find. Repeat every few weeks until you find the amount that keeps your dog at an ideal body condition.
That's it. No complex formula required. Regular weigh-ins and the rib check will tell you everything you need to know.