The numbers, plainly

A moderate Pilates session burns roughly 175–250 calories an hour for an average adult; a jumpboard or dynamic reformer class can reach 300–400. Running the same hour burns 600 or more.

If the goal is calorie expenditure, Pilates is an inefficient choice, and it is worth saying that clearly rather than implying otherwise.

Where it does contribute

Three ways. It builds muscle, which raises resting metabolic rate modestly. It improves movement quality and reduces injury risk, which keeps people doing the more demanding exercise that does burn calories. And it is sustainable — people continue it for years, which no amount of theoretical efficiency matches.

That last point matters most. The best exercise for weight management is the one someone will still be doing in two years.

Approximate hourly calorie expenditure
ActivityCalories/hourNotes
Mat Pilates, moderate175–250Varies with pace
Reformer, dynamic250–350Higher with jumpboard
Brisk walking250–350Highly sustainable
Cycling, moderate450–600
Running, moderate600–800

Diet does the work

Weight change is dominated by energy intake, and exercise is a weak lever by comparison — an hour of Pilates is roughly one large muffin. This is not a reason to skip exercise; it is a reason not to expect exercise alone to produce weight loss.

The most reliable pattern is dietary change for weight loss and exercise for body composition, health and maintaining the loss.

What to expect from Pilates specifically

Changes in shape and posture often appear before changes on the scale, because improved alignment and muscle tone alter how the body carries itself. People frequently report clothes fitting differently well before their weight changes meaningfully.