Inches of Water Per Week to mm Per Day Converter
Instantly convert weekly watering totals in inches to a daily millimetre irrigation rate. Accurate, free calculator for lawns, gardens and greenhouses.
Calculate the Daily Watering Rate
Enter the weekly watering amount in inches below to get an instant, precise conversion to millimetres per day, along with the weekly total in millimetres.
Watering Converter
Enter the weekly inches to see the daily mm rate
Typically ranges from 1 to 2 inches per week for lawns and gardens
Use 7 for an even daily average, or fewer if you water on set days
Helps provide relevant context for the converted rate
Converted Rate
Based on standard inches-to-millimetres conversion
Weekly Inches to Daily mm Reference Chart
Standard conversions for quick lookup when planning irrigation schedules, based on watering spread evenly across 7 days.
| Water Per Week (inches) | Per Day (mm) | Per Week (mm) | Typical Use |
|---|---|---|---|
| 0.5″ | 1.81 mm | 12.7 mm | Drought-tolerant plants |
| 1.0″ | 3.63 mm | 25.4 mm | Established lawn (minimum) |
| 1.5″ | 5.44 mm | 38.1 mm | Typical lawn watering guideline |
| 2.0″ | 7.26 mm | 50.8 mm | Vegetable garden in warm weather |
| 2.5″ | 9.07 mm | 63.5 mm | Newly seeded lawn or transplants |
| 3.0″ | 10.89 mm | 76.2 mm | Hot climate or sandy soil |
Watering Rate Conversion FAQ
Everything you need to know about converting weekly watering inches to a daily millimetre rate.
To convert inches of water per week to millimetres per day, multiply the inches by 25.4 to get millimetres, then divide by 7. For example, 1 inch per week multiplied by 25.4 is 25.4, divided by 7 equals about 3.63 millimetres per day.
1 inch of water per week is approximately 3.63 millimetres per day. This assumes the water is applied evenly across all 7 days of the week.
Most established lawns need around 1 to 1.5 inches of water per week, including rainfall, which is roughly 3.6 to 5.4 millimetres per day. Needs can be higher in hot, dry weather or for sandy soils that drain quickly.
Yes. Rainfall should be included when working out total weekly water inches, since plants and lawns respond to total moisture regardless of the source. Many gardeners use a rain gauge and top up irrigation only for the shortfall.