Electricity is usually a miner's largest ongoing cost: power at the wall in kilowatts, times 24 hours, times your price per kWh, gives your daily electricity spend. Compare that against what a rig actually pays out and you know whether it's running at a real profit — not just a theoretical one based on advertised hashrate.
The payout side of that comparison is easiest to see when every coin you mine sits in one place. Scrypt Wallet shows real, current balances and prices across your coins side by side, so a day's or a week's real earnings are one glance away instead of several pool dashboards.
Create a free account to see your real mining payouts against your real costs, non-custodially.