How Much Should I Feed My Senior Dog?

Last updated: June 2026 · 10 min read

"How much do I feed my old dog?" is one of the most-asked — and worst-answered — questions in dog nutrition. The bag's feeding chart is built for a generic adult, and an ageing dog isn't that. Our senior cost-vs-value guide showed why older dogs eat less and what that means for your budget; this page answers the practical question underneath it: exactly how much food is the right amount, and how do you work it out for your dog?

No product rankings here — for our actual picks see the best senior dog food roundup. This is the portion-and-calorie maths, in plain English. (Got a puppy instead? The same formula runs the other way in our how much to feed a puppy guide.) Prefer to skip the maths? Our dog food calculator does every step below for you — enter the weight and it returns the grams.

A note up front: these are representative figures to illustrate the method, not a substitute for veterinary advice. Every dog differs, and any sudden change in appetite or weight is a vet visit, not a portion tweak.

Start With Calories, Not Cups

The single biggest mistake owners make is feeding by volume — "two scoops" — when what actually matters is calories. A scoop of one food can hold twice the energy of a scoop of another, and an old dog's needs are lower than the bag assumes. So we start from calories and convert to grams at the end.

There's a simple, vet-used way to estimate a dog's daily energy need in two steps:

1. Resting Energy Requirement (RER) — the calories a dog burns just existing: RER = 70 × (bodyweight in kg)0.75.
2. Maintenance Energy Requirement (MER) — RER multiplied by an activity factor. For a typical neutered, less-active senior that factor is about 1.2–1.4 (a sprightly older dog sits higher; a very sedentary or overweight-prone one lower, around 1.0–1.2).

That activity factor is where age does its work. A young, entire, active adult might be fed at 1.6–1.8 × RER; the same dog as a steadier senior drops toward 1.2–1.4. Same dog, same formula — the multiplier shrinks, and the bowl shrinks with it.

Senior Calorie & Portion Table (June 2026, UK)

Here's the maths done for you. The calorie column is RER × 1.2–1.4 (a typical senior maintenance band). The grams column converts the midpoint of that band into a daily weight of a representative 365 kcal/100g grain-free kibble — always check your own food's label, since energy density varies.

Two things to notice. First, the calorie need climbs slower than weight — a 40kg dog isn't eight times a 5kg dog's portion, because the ^0.75 exponent reflects how metabolism scales. Second, these are starting points to test, not commandments. Feed at this level for 2–3 weeks, then adjust up or down based on your dog's actual body condition (see below).

Turning Calories Into Grams of Any Food

The table assumes kibble, but the conversion works for anything once you find the food's energy density on the label (metabolisable energy, usually kcal per 100g):

Grams per day = (daily calories ÷ kcal per 100g) × 100

So the same 15kg senior needing ~675 kcal/day eats:

• Kibble at 365 kcal/100g → ~185 g/day (cupboard-stable, calorie-dense).
• Wet food at ~95 kcal/100g → ~710 g/day — far more weight of food for the same energy, because it's ~75% water. That's why wet food looks like "more" in the bowl.
• Fresh-cooked at ~140 kcal/100g → ~480 g/day, typically pre-portioned to your dog's calorie need by the subscription.

This is also why mixing foods needs care: a topper isn't free calories. If you add wet or fresh on top of kibble, take an equal share of calories out of the kibble — our topper-without-overfeeding guide walks through the exact displacement maths, which matters most for seniors whose total need is already low.

Worked Example: A 14kg Senior Cocker Spaniel

The table above lists round weights, but most owners arrive here with a specific dog in mind — so let's run the maths end-to-end for one of the UK's most common older dogs, a 14kg senior Cocker Spaniel (the breed sits squarely in the 12–16kg band where small-but-not-tiny dogs live). Follow these three steps and you can repeat them for any dog:

1. RER = 70 × 14^0.75 = 70 × 7.24 ≈ 507 kcal just to exist.
2. MER = 507 × a senior factor of 1.2–1.4 ≈ 608–709 kcal/day, so we'll work from the midpoint, ~660 kcal.
3. Convert to grams with (660 ÷ kcal-per-100g) × 100 for whatever you actually feed.

That single 660 kcal target lands very differently depending on the food:

• Grain-free kibble (365 kcal/100g) → ~180 g/day, i.e. roughly 90 g per meal split across two meals.
• Wet food (~95 kcal/100g) → ~695 g/day — about 1¾ standard 400g trays, which looks like a feast but is the same energy, just mostly water.
• Fresh-cooked (~140 kcal/100g) → ~470 g/day, usually delivered pre-portioned to that number by the subscription.

Here's the part that matters for a small senior's wallet, not just its waistline. A 14kg Cocker needs barely a third of the food a 40kg senior Labrador does, so the wet or fresh premium that feels extravagant on a big dog becomes genuinely affordable here — the very point our senior cost-vs-value guide makes. At ~470 g/day of fresh food, a small senior is exactly the dog for whom upgrading to a moisture-rich, aromatic diet (which also helps a fading appetite and worn teeth) costs the least and pays back the most. Run the same three steps for your dog's weight; the method doesn't change, only the multiplier on the scales.

The Other Extreme: A 3kg Senior Yorkshire Terrier

Run the same three steps for a tiny dog and the headline lesson flips from wallet to precision. Take a 3kg senior Yorkshire Terrier:

1. RER = 70 × 3^0.75 = 70 × 2.28 ≈ 160 kcal to exist.
2. MER = 160 × 1.2–1.4 ≈ 191–223 kcal/day, midpoint ~207 kcal.
3. Convert to grams with the same (207 ÷ kcal-per-100g) × 100.

That ~207 kcal target works out to roughly:

• Grain-free kibble (365 kcal/100g) → ~57 g/day.
• Wet food (~95 kcal/100g) → ~218 g/day — about half a 400g tray.
• Fresh-cooked (~140 kcal/100g) → ~148 g/day.

Here the danger isn't cost — fresh feeding a 3kg dog is almost trivially cheap — it's that 57 g of kibble is a small handful, so eyeballing the bowl is a recipe for over-feeding. A 10 g "splash extra" that's invisible on a Labrador's portion is nearly a fifth of a Yorkie's entire day, and small dogs carry surplus weight as a much larger fraction of their frame. Weigh a senior toy's food on a kitchen scale, not a scoop. Two other toy-specific notes: split the day into three or four small meals rather than two — tiny dogs have little energy reserve and can dip into low blood sugar on a long empty stomach, a risk that doesn't fully retire with age — and don't crash-diet a toy senior; trim only ~10% at a time and recheck, because a small dog reaches "too thin" alarmingly fast. The maths is identical to the big-dog case; only the multiplier on the scales — and the cost of getting it wrong by a few grams — changes.

The Real Test: Body Condition, Not the Bag

Every number above is a hypothesis to check against your actual dog. The gold standard is body condition scoring, and it takes ten seconds:

• Ribs: you should feel them easily with light pressure, like the back of your hand — but not see them on a short-coated dog.
• Waist (from above): a clear hourglass tuck behind the ribcage.
• Belly (from the side): an upward tuck from chest to hindquarters, not a level or sagging line.

If the ribs are disappearing under a pad of fat and the waist is gone, cut the daily amount ~10% and recheck in a fortnight. If the ribs, spine and hips are sharply visible, increase it — and book a vet check, because unexplained weight loss in an older dog can flag dental pain, kidney disease, dental loss or other illness rather than simple under-feeding. In old age, a changing shape is information; act on the dog in front of you, not the chart on the bag.

Senior-Specific Adjustments

• Split into two meals. Easier digestion, steadier energy, and gentler on a senior that gets queasy on an empty stomach. It doesn't change the daily total — only the rhythm.
• Keep protein high, calories trimmed. Slim an old dog by cutting portion, never protein quality — sarcopenia (age-related muscle loss) is the enemy, and protein is the defence. (More on this in the cost-vs-value guide.)
• Re-weigh quarterly. Senior needs drift faster than adult ones. A portion that's right at ten can be 10% too much at thirteen. Recalculate from the table when the weight or activity changes.
• Account for treats. Treats and chews are calories too — keep them under ~10% of the daily total, and subtract them from the meal maths for a dog that's gaining.
• Watch for the appetite trap. A senior going off its food isn't a budgeting win — it's often the cue for a warm, aromatic wet or fresh topper to tempt it back, or a vet visit if it persists.

The Bottom Line

• Feed calories, not cups. Estimate need with RER (70 × kg^0.75) × a senior activity factor of ~1.2–1.4, then convert to grams using your food's label.
• Older dogs need 10–20% fewer calories than at their adult peak — the same portion quietly fattens an ageing dog.
• Body condition beats the bag chart. Feel for ribs, look for a waist, and adjust the portion ±10% every couple of weeks.
• Trim portions, never protein. Protect muscle by keeping protein quality high while calories come down.
• Sudden change = vet, not maths. A gentle taper is normal ageing; an abrupt swing in weight or appetite needs a check-up.

Ready to choose the food itself? See our best senior dog food picks, the cost-vs-value breakdown for ageing dogs, or — for a big old friend — the best food for senior Labradors.

Frequently Asked Questions