Clothesline vs Dryer Cost Calculator

Introduction

This calculator helps you compare two common ways to dry laundry: using an electric clothes dryer or air drying on a clothesline (or drying rack). A dryer is fast and predictable, but it uses electricity every load. Line drying typically uses no electricity, so the ongoing operating cost is close to $0. By entering a few numbers from your household and utility bill, you can estimate:

• Dryer cost per load based on energy use (kWh) and your electricity rate
• Annual dryer cost based on how many loads you run each week
• Annual CO₂ emissions from dryer electricity use based on your grid’s carbon intensity

The results are useful for budgeting, deciding whether to line dry more often, and understanding the climate impact of routine household energy use. You can also use the calculator to compare a standard resistance dryer to a more efficient heat pump dryer by changing the “kWh per load” value.

How to use the calculator

1. Enter Laundry Loads per Week: count how many dryer cycles you typically run in an average week. If your laundry varies seasonally, use a typical week or average across the year.
2. Enter Dryer Energy per Load (kWh): many dryers use roughly 2–6 kWh per load depending on model, settings, and load size. If you have an energy monitor or a smart plug, use your measured value. Otherwise, start with the default and adjust.
3. Enter Electricity Rate ($/kWh): find this on your utility bill. If you have time-of-use pricing, you can model off-peak drying by entering your off-peak rate.
4. Enter Grid CO₂ per kWh (kg): this is the carbon intensity of your electricity. If you don’t know it, a common rough range is 0.1–0.9 kg CO₂/kWh depending on your region and generation mix.
5. Select Compare to calculate the dryer’s per-load cost, annual cost, and annual CO₂. Use Copy Result to paste the output into a note, spreadsheet, or household budget.

Formula and assumptions

The calculator treats line drying as having zero electricity use per load. It focuses on the operating cost and operating emissions of the dryer. (If you want to include the purchase price of a clothesline, rack, or dryer, you can compare those separately as a one-time cost.)

Let: L = loads per week, E = dryer energy per load (kWh), R = electricity rate ($/kWh), G = grid emissions factor (kg CO₂/kWh).

Then:

• Cost per load = E × R
• CO₂ per load = E × G
• Annual dryer cost = (E × R) × L × 52
• Annual dryer CO₂ = (E × G) × L × 52

The “52” assumes 52 weeks per year. If your laundry habits change significantly during part of the year (for example, more indoor drying in winter), you can run the calculator twice with different assumptions and combine the results.

Worked example

Suppose you run 5 loads per week, your dryer uses 3.0 kWh per load, your electricity rate is $0.15/kWh, and your grid emits 0.45 kg CO₂/kWh.

• Cost per load = 3.0 × 0.15 = $0.45
• Annual dryer cost = 0.45 × 5 × 52 = $117.00
• CO₂ per load = 3.0 × 0.45 = 1.35 kg CO₂
• Annual dryer CO₂ = 1.35 × 5 × 52 = 351.0 kg CO₂

If you line dry half of those loads, you’d roughly cut those annual totals in half (assuming the same loads and that line drying replaces dryer use). In practice, some households use a hybrid approach—air drying most of the way and finishing briefly in the dryer—which still reduces energy use.

Limitations and what this calculator does not include

This tool is intentionally simple so you can get a quick, transparent estimate. As a result, it does not model every real-world detail. Keep these limitations in mind when interpreting the results:

• Dryer energy varies by load and settings. Heavy towels, high-heat cycles, and overloading can increase kWh per load. Heat pump dryers often use substantially less energy than conventional resistance dryers.
• Gas dryers are not covered. If your dryer uses natural gas or propane, the cost and emissions calculation would be different.
• Line drying may have small indirect costs. Indoor drying can increase humidity, sometimes leading to extra ventilation or dehumidifier use. Outdoor drying may require a rack, line, or occasional replacement of clothespins.
• Time and convenience are not priced. The calculator reports dollars and CO₂, but not the value of your time or the convenience of faster drying.
• Fabric wear and replacement are not included. Some people find air drying extends garment life, which could reduce long-term clothing costs and waste.
• Carbon intensity can change. Grid CO₂ per kWh varies by region and time of day; using an annual average is a simplification.

Practical guidance for interpreting results

A dryer’s per-load cost is often small, which can make the annual total easy to overlook. But small recurring costs add up. If your result shows $100–$300 per year, that can be meaningful over the life of a dryer—especially if you can line dry during warm months. Likewise, the CO₂ estimate helps you understand the climate impact of a routine household habit.

If you want to reduce dryer use without fully switching to line drying, consider these common strategies:

• Spin more water out (higher washer spin speed) so the dryer runs less.
• Dry similar fabrics together to avoid over-drying lighter items.
• Use moisture-sensing modes when available instead of timed cycles.
• Air dry first, finish briefly in the dryer to soften towels or reduce wrinkles.
• Clean the lint filter to maintain airflow and efficiency.

The calculator below focuses on the dryer’s electricity use. If you line dry, your operating electricity cost for drying is effectively $0, so the “savings” are approximately the dryer totals shown in the results.