# Water Usage Calculator for SoCal Homes | Total Tankless > Free calculator: estimate your home URL: https://socaltotaltankless.com/tools/water-usage-calculator/ FREE\_TOOL · TL\_01 · NO SIGN-UP # Household Water Usage Calculator Estimate how many gallons your household uses each month, how much of it is hot water, and what CA-standard fixtures could save you. TL\_01 · YOUR\_HOUSEHOLD People in Household1 person2 people3 people4 people5 people6+ people Showers per Person per DayEvery other dayOnce dailyTwice daily Average Shower Length5 minutes (quick)8 minutes (average)12 minutes (long)20+ minutes (very long) Showerhead Flow RateOlder showerhead (2.5 GPM)California standard (1.8 GPM)Low-flow (1.5 GPM)Rain or dual head (3+ GPM) Look for a small GPM stamp near the threaded connection on the showerhead. Toilet TypePre-1994 toilet (3.5 gal/flush)Standard (1.6 gal/flush)High-efficiency (1.28 gal/flush)Dual-flush (about 1 gal avg) Lawn & Garden WateringNo outdoor wateringSmall garden or plantersMedium lawnLarge lawn Gallons per week during the dry season. Swimming Pool or SpaNo poolSpa or small poolMedium poolLarge pool Gallons topped off each month to replace evaporation. Water Rate ($ per 1,000 gal) Rough Southern California figure. Check your bill for your rate (1 HCF = 748 gallons). Estimated Monthly Water Use 2,884 gal Hot Water per Day 42 gal Monthly Water Cost $28.84 Per Person per Day 32 gal Where Your Water Goes - Showers1,296 gal · 45% - Toilets864 gal · 30% - Sinks450 gal · 16% - Dishwasher80 gal · 3% - Laundry194 gal · 7% Savings With California-Standard Fixtures About 173 gallons a month $1.73/month - Moderate hot water demand Daily volume is manageable, but a tankless unit can still save space and standby energy. Compare upfront and lifetime costs before you decide. Compare tank vs. tankless → [/guide/tank-vs-tankless-water-heater/ →](/guide/tank-vs-tankless-water-heater/) - Plan for scale buildup Every gallon of hot water leaves minerals in the heat exchanger. With Southern California's hard water, an annual flush is a common baseline, and heavy use can justify service more often. Flush vs. full maintenance → [/guide/full-tankless-maintenance-vs-basic-flush/ →](/guide/full-tankless-maintenance-vs-basic-flush/) Estimates are based on typical usage patterns and fixture flow rates. Actual water use varies with habits, appliance efficiency and water pressure. Your utility bill is the most accurate record of your use. NEXT\_STEP: FREE\_VIRTUAL\_ESTIMATE ## Turn These Numbers Into a Tankless Plan Send us your results and we'll follow up with a free virtual estimate for a tankless unit sized to your household. We reply during business hours, Monday–Friday. - FACTORY-CERTIFIED TECHNICIANS - FREE VIRTUAL ESTIMATES - NO HIDDEN ADMIN FEES - MON–FRI 9 AM–5 PM - LA · ORANGE · VENTURA COUNTIES - SERVING SOCAL SINCE 2021 STATUS: FACTORY-CERTIFIED TECHNICIANS | FREE VIRTUAL ESTIMATES | NO HIDDEN ADMIN FEES | MON–FRI 9 AM–5 PM | LA · ORANGE · VENTURA COUNTIES | SERVING SOCAL SINCE 2021 /// STATUS: FACTORY-CERTIFIED TECHNICIANS | FREE VIRTUAL ESTIMATES | NO HIDDEN ADMIN FEES | MON–FRI 9 AM–5 PM | LA · ORANGE · VENTURA COUNTIES | SERVING SOCAL SINCE 2021 /// 01\_METHOD ## How This Calculator Estimates Your Use Every number comes from the household details you enter plus typical fixture flow rates. Here is each assumption. | Step | Assumption | | --- | --- | | 01 | Monthly shower use (gallons) | | 02 | Toilets: 6 flushes per person per day | | 03 | Kitchen and bath sinks: about 5 gallons per person per day | | 04 | Dishwasher: about 4 gallons per load | | 05 | Laundry: about 15 gallons per load, 1 load per person per week | | 06 | Outdoor watering plus pool top-off | | 07 | Total monthly use (gallons) | | 08 | Monthly hot water: ~70% of shower water, ~50% of sink water, all dishwasher water, ~25% of laundry | | 09 | Average hot water per day | | 10 | Average use per person per day | | 11 | Monthly water cost | | 12 | Monthly gallons saved with 1.8 GPM showerheads and 1.28 gal/flush toilets | | 13 | Monthly water savings in dollars | 02\_NEXT\_STEPS ## What to Do With Your Results Heavy hot water use is the most common reason SoCal homeowners switch to tankless, and the reason to keep a tankless unit descaled. SC\_01 Tankless Water Heater Installation Turn-key replacement of your tank with an on-demand tankless unit, including code-required venting and gas line upgrades. [/tankless-water-heater-installation/ →](/tankless-water-heater-installation/) SC\_03 Tankless Water Heater Maintenance Comprehensive preventative maintenance: full flush, internal fan cleaning, flame rod cleaning and gas pressure set to factory spec. [/tankless-water-heater-maintenance/ →](/tankless-water-heater-maintenance/) What Size Tankless Water Heater Do I Need? [/guide/what-size-tankless-water-heater-do-i-need/ →](/guide/what-size-tankless-water-heater-do-i-need/) Tank vs. Tankless for SoCal Homes [/guide/tank-vs-tankless-water-heater/ →](/guide/tank-vs-tankless-water-heater/) Full Maintenance vs. Basic Flush [/guide/full-tankless-maintenance-vs-basic-flush/ →](/guide/full-tankless-maintenance-vs-basic-flush/) 03\_FAQ\_LOG ## Water Usage Calculator Questions STILL\_HAVE\_QUESTIONS Send photos of your setup and we'll reply with answers and a price estimate during business hours. Get a Free Virtual Estimate [/contact/ →](/contact/) (301) 555-8979 [tel:+13015558979 →](tel:+13015558979) ### How much water does a typical household use? The EPA estimates the average American family uses more than 300 gallons of water a day at home, including outdoor watering. Indoor use is usually led by toilets, showers and laundry. Your own number depends on household size, fixture flow rates and how much you water outside. ### How much of my water use is hot water? In most homes, showers are the biggest hot water load, followed by sinks, the dishwasher and warm laundry cycles. This calculator assumes about 70% of shower water, half of sink water, all dishwasher water and a quarter of laundry water is heated. Those shares shift with your habits and inlet water temperature. ### Will a tankless water heater lower my water use? Not by itself. A tankless unit saves energy by heating water only when you use it, with no tank losing heat around the clock. Water savings come from efficient fixtures like 1.8 GPM showerheads and high-efficiency toilets, which is what the savings figure in this calculator shows. ### Can I size a tankless water heater from my daily hot water use? Daily volume tells you how hard the unit will work, but tankless heaters are sized by peak flow: how many gallons per minute you run at the same time, and how much the unit must raise the incoming water temperature. Our sizing guide walks through that math, and our free virtual estimate confirms it for your home. ### How often should a tankless water heater be flushed in Southern California? An annual flush is a common baseline in Southern California because hard water leaves scale in the heat exchanger. Homes with heavy hot water use or very hard water may need service more often. Check your manufacturer's warranty terms, since scale damage is often excluded. ![Technician finishing a clean tankless water heater installation in a Southern California garage](/images/misc/factory-certified-technician-finishing-a-clean-wal.webp) NEXT\_STEP: FREE\_VIRTUAL\_ESTIMATE ## Ready for Endless Hot Water? Send photos of your current water heater and get a written price range for a tankless unit sized to your household. No hidden admin fees. Get a Free Virtual Estimate [/contact/ →](/contact/) Call (301) 555-8979 [tel:+13015558979 →](tel:+13015558979) - Factory-certified technicians - No hidden admin fees - Mon–Fri, 9 AM–5 PM