How much oil is in a transformer based on its rating?

Oil volume depends on transformer design, cooling class, voltage level, and tank geometry, not only kVA or MVA rating. Higher ratings generally require larger tanks, more radiators, and greater oil volume, but two transformers with the same rating can differ significantly. The most accurate source is the nameplate and manufacturer documentation, which often lists oil weight or volume. For planning, utilities use typical ranges by class, but procurement and maintenance should rely on the specific unit data to ensure correct logistics and containment sizing.