★ EVERYDAY · LAUNDRY · COMPARISONS
Cold washing saves $115.80 a year at the defaults: $13.26 for cold against $129.06 for hot. Enter your loads, electricity price, water volume, and temperatures to see what your own laundry habit costs — this is an energy-only comparison, so detergent and machine wear are left out on both sides.
A cold wash pays only for running the machine: 0.30 kWh per load in this model. A hot wash pays that too, plus the energy to heat the wash water — and heating water is the expensive part. This calculator prices both at your electricity rate, so the comparison follows your bills rather than a national average.
At the defaults, the machine itself uses 0.30 kWh per load. Over 260 loads that is 78 kWh, and at $0.17 per kWh a cold wash costs $13.26 a year, or $0.05 per load. A hot wash adds the heat for 50 litres of water: 50 × 4.186 × 45 = 9,418.5 kJ, which is 2.62 kWh, so a hot load uses 2.92 kWh in total. Over 260 loads that is 759.2 kWh, costing $129.06 a year, or $0.50 per load. The gap is $115.80 a year, or about $0.45 per load, in cold's favour. Per-load energy figures here are rounded to two decimals before the yearly totals are worked out, so the page figures, the live calculator, and the companion guide all agree exactly. The gap is not fixed: it grows to $204.36 a year at $0.30 per kWh, and to $185.28 a year at 8 loads a week, while light users save $69.48 at 3 loads a week. A warm wash at 40°C sits in between at $77.35 a year: it saves $51.71 against hot, but still costs $64.09 more than cold.
This is an energy-only comparison. It assumes the machine draws 0.30 kWh per load for tumbling, pumping, and spinning on either setting, heats a full 50 litres per hot or warm load from the stated inlet temperature, and runs 52 weeks a year at the stated loads per week. It leaves out detergent, which differs by wash temperature and product, and it leaves out machine wear, purchase price, and drying. Real machines vary: front-loaders often use less water than 50 litres, which shrinks the hot-wash penalty, and cold inlet water in winter raises it. Enter your own water volume and inlet temperature to see your own gap, and treat the result as the yearly energy gap at your rate, not a whole-cost-of-laundry figure.
| Output | Formula | What it means |
|---|---|---|
| Loads per year | Loads per week × 52 | 5 × 52 = 260 loads at the defaults. |
| Heat for a hot load | 50 L × 4.186 × (60 − 15)°C ÷ 3,600 | 9,418.5 kJ = 2.62 kWh per load at the defaults. |
| Hot energy per load | 0.30 kWh + 2.62 kWh | 2.92 kWh per load at the defaults. |
| Cold cost per year | 0.30 kWh × 260 loads × $0.17 | 78 kWh × $0.17 = $13.26 a year. |
| Hot cost per year | 2.92 kWh × 260 loads × $0.17 | 759.2 kWh × $0.17 = $129.06 a year. |
| Warm energy per load | 0.30 kWh + (50 × 4.186 × 25 ÷ 3,600) | 0.30 + 1.45 = 1.75 kWh per load at the defaults. |
| Warm cost per year | 1.75 kWh × 260 loads × $0.17 | 455 kWh × $0.17 = $77.35 a year. |
| Yearly saving | Hot total − cold total | $129.06 − $13.26 = $115.80 a year for cold. |
| Cost per load | Yearly total ÷ 260 loads | $0.05 cold vs $0.50 hot per load. |
This is an energy model, not a meter reading. It assumes the machine heats the full stated water volume on every hot or warm load, which overstates the penalty for machines that heat only part of their water or use less than 50 litres, and it assumes the same 0.30 kWh of machine energy on every setting. It does not price detergent, stain performance, or hygiene: cold water with a modern detergent cleans everyday laundry well, but heavily soiled items, cloth nappies, and bedding after illness may still need a hot wash, and that exception costs only a few hot loads a year. Check your machine manual for its real water use and your bill for your real rate, and treat the result as the yearly energy gap at your settings.
Bright Side Kit. "Cold Wash vs Hot Wash: Yearly Laundry Cost Calculator." https://brightoolbox.com/cold-wash-vs-hot-wash/ Accessed October 24, 2026.At the defaults, $13.26 a year: 0.30 kWh per load over 260 loads is 78 kWh, at $0.17 per kWh. That is $0.05 per load, for machine energy only.
At the defaults, $129.06 a year: 2.92 kWh per load over 260 loads is 759.2 kWh, at $0.17 per kWh. That is $0.50 per load, for machine energy plus water heating.
$115.80 a year at the defaults: $129.06 for hot minus $13.26 for cold, at 5 loads a week and $0.17 per kWh. At 8 loads a week the saving is $185.28; at $0.30 per kWh it is $204.36.
Because heating water takes far more energy than running the machine. Heating 50 litres from 15°C to 60°C needs 2.62 kWh, while the machine itself uses only 0.30 kWh per load.
It halves the penalty: a 40°C wash costs $77.35 a year at the defaults, saving $51.71 against hot while still costing $64.09 more than cold. It suits bedding and towels where you want some heat.
For everyday laundry with a modern detergent, yes in most cases. Heavily soiled items, cloth nappies, and bedding after illness are the usual exceptions that still benefit from a hot wash.
No, deliberately: this is an energy-only comparison, so detergent is left out on both sides. Detergent cost depends on product and dose, not on wash temperature alone.
Enter your real volume and the hot-wash penalty shrinks with it: less water heated means less heat energy. Front-loaders commonly use less than the 50-litre default, so check your manual.