Sardines carry noticeably more protein; mackerel carries more fat. Per 100 g the calories are almost identical — 205 for mackerel and 208 for sardines — but sardines deliver 24.6 g of protein to mackerel’s 18.6 g, with less total fat (11.5 g against 13.9 g) and less than half the saturated fat (1.53 g against 3.26 g).
The one figure that is not a like-for-like comparison is sodium: 307 mg for sardines against 90 mg for mackerel. Our sardine record is the canned fish and our mackerel record is raw, and canning is where almost all of that salt comes from. A fresh sardine is not a high-sodium food.
| Nutrient | Mackerel | Sardines |
|---|---|---|
| Calories | 205 kcal | 208 kcal |
| Protein | 18.6 g | 24.62 g ✓ |
| Total Carbohydrate | 0 g | 0 g |
| Dietary Fiber | 0 g | 0 g |
| Total Sugars | 0 g | 0 g |
| Total Fat | 13.9 g | 11.45 g |
| Saturated Fat | 3.26 g | 1.53 g ✓ |
| Sodium | 90 mg ✓ | 307 mg |
Notable compounds in each
When to choose each
Reach for sardines when protein per calorie matters, or when you want an oily fish that keeps in a cupboard — they are also eaten bones-in, which is why they are one of the few non-dairy foods that supplies meaningful calcium. Reach for mackerel for a richer, fattier fillet and a milder sodium load, and when you are cooking fresh rather than opening a tin. Both are among the strongest sources of long-chain omega-3 in the database.
Mackerel vs sardines nutrition per 100g
Neither fish carries carbohydrate or fibre, so the whole comparison sits in the protein and fat columns. Sardines also edge mackerel on potassium, 397 mg against 314 mg.
Read the sodium figure as a property of the tin rather than the fish. Draining the oil or brine removes some of it, and tins sold in spring water are usually lower again — worth checking the label if you eat them often.
Common questions
Which is healthier, mackerel or sardines? Sardines come out ahead on the numbers: more protein, less saturated fat and more potassium for the same calories. Mackerel is the better choice if you are watching sodium and buying fresh. Both are oily fish and both are good sources of omega-3.
Do sardines have more protein than mackerel? Yes — 24.6 g per 100 g against 18.6 g, about a third more.
Are sardines high in sodium? Canned ones are, at around 307 mg per 100 g, because salt is added in the canning process. Fresh sardines are not. Draining the tin and choosing spring water over brine both bring the figure down.
Can you eat sardines and mackerel every day? Both are oily fish, which official advice generally suggests eating a couple of times a week rather than daily, partly because oily fish accumulate more contaminants than white fish. Sardines and mackerel are both small, short-lived species and sit at the lower end of that concern.