Match the billing dates before anything else
The first thing worth checking is the billing period on each bill: the start date, the end date, and the number of days covered. If one bill covers 30 days and the other covers 33, a higher total on the second one may simply reflect three extra days of usage rather than any real change in your habits or the price you're being charged.
A quick way to adjust for this is to divide each bill's total by its number of days to get a rough daily cost, then compare those daily figures instead of the totals directly. It won't be perfectly precise, since usage isn't always spread evenly across a billing period, but it removes most of the distortion caused by different period lengths.
Look at kWh usage, not just the dollar total
Electric bills typically list total kilowatt-hours (kWh) used during the period. Comparing kWh directly tells you whether you actually used more electricity, separate from any change in price. If kWh usage is similar across both bills but the total cost differs, the explanation is more likely to involve rates or fees than your actual consumption.
Many utilities also show a graph of recent monthly usage directly on the bill, which can make a usage change easier to spot at a glance than reading the raw kWh figures. That built-in comparison is a reasonable starting point before pulling numbers from two separate bills yourself.
Check the rate, or effective cost per kWh
You can estimate an effective rate by dividing the total energy charge by the kWh used. Comparing that effective rate across two bills can reveal a price change that would otherwise be hidden inside a total that also reflects a different usage amount. A higher effective rate on one bill, even with similar usage, points toward a price or plan change rather than a usage change.
This effective-rate calculation is also useful if you're comparing bills from different plans or providers, since it puts them on the same per-unit basis rather than comparing two totals that may cover different amounts of usage entirely.
Separate fixed charges from variable ones
Most bills include a fixed charge that doesn't move with usage, alongside variable charges that scale with kWh consumed. Some also include a fuel or adjustment charge that can shift from month to month based on the utility's own costs, independent of anything you did differently. Identifying which line items are fixed and which are variable makes it easier to see which part of the bill actually changed.
A fixed charge that increased between two bills points toward a plan or rate change rather than anything about your household's usage, since that charge applies regardless of how much electricity you used that period. Separating it out avoids mistakenly attributing a fixed-charge increase to higher consumption.
Account for credits, fees, and seasonal context
Watch for one-time credits or fees that apply to only one of the two bills, since these can shift a total without reflecting an ongoing change. It's also reasonable to note weather or seasonal context, such as an unusually hot or cold stretch, as a possible contributor to a usage change, but that connection is worth confirming with the actual usage numbers rather than assumed just because the weather felt notable that month.
Going through these checks in order, from billing dates down to credits and context, gives you a clearer answer than eyeballing two totals side by side. It also puts you in a better position to describe the specific difference if you ever need to ask the utility a question about either bill.