TryBuildCalcElectricity Running Cost Calculator (Day / Week / Month / Year Cost Estimate)
Calculate running cost instantly.
🕒 Last updated: August 28, 2026
Inputs
Equipment
Pick a preset for a typical starting point, or choose Custom and enter your equipment's actual nameplate watts and usage pattern.
Equipment 1
ℹ️For equipment that draws a small amount of power even when off but still plugged in.
Equipment 2
ℹ️For equipment that draws a small amount of power even when off but still plugged in.
Equipment 3
ℹ️For equipment that draws a small amount of power even when off but still plugged in.
Electricity Rate
ℹ️Found on your utility bill — sometimes called the energy charge or price per unit (1 unit = 1 kWh).
ℹ️A fixed monthly fee your utility charges regardless of usage — include it for a full bill estimate, leave blank to see energy cost only.
Estimated Monthly Cost: ₹127.15
From 847.68 kWh/month at ₹0.1500/kWh
Cost by Period (Energy Only)
| Period | kWh | Cost |
|---|---|---|
| Day | 27.85 | ₹4.18 |
| Week | 194.95 | ₹29.24 |
| Month | 847.68 | ₹127.15 |
| Year | 10,172.21 | ₹1,525.83 |
Equipment Breakdown (Monthly)
| Equipment | kWh | Cost | Share |
|---|---|---|---|
| Refrigerator | 109.58 | ₹16.44 | 12.9% |
| Central A/C | 730.50 | ₹109.58 | 86.2% |
| LED Bulb | 7.61 | ₹1.14 | 0.9% |
Assumptions Used
Month = 30.4375 days (365.25 ÷ 12) average, year = 365.25 days — avoids a lumpy figure tied to any one calendar month. Uses a flat electricity rate, not tiered or time-of-use pricing. This is a reference estimate — confirm against your actual utility bill and rate structure.
Planning backup power instead of running cost? UPS Battery Capacity Calculator →
Sizing a generator for this same equipment list instead? Generator Size Calculator →
What Is an Electricity Running Cost Calculator?
An electricity running cost calculator estimates what it costs to operate equipment — one item or many together — based on its wattage, how often it's used, and your electricity rate. It converts usage into kilowatt-hours (kWh) and multiplies by your rate to show cost per day, week, month, and year.
This is a different calculation from the Panel Size or Generator Size calculators (which size electrical capacity, not ongoing cost) — use this tool to answer "what does this cost me to run," compare equipment options, or estimate a full bill.
Why calculating running cost matters:
- Large, long-running loads (HVAC, water heating) usually dominate a bill far more than most people expect
- Standby/phantom power from always-plugged-in electronics is easy to overlook but adds up over a year
- Comparing running cost before buying a replacement appliance can reveal whether a higher-efficiency model actually pays for itself
- Usage pattern (hours/day, days/week) matters as much as wattage — the same appliance used differently costs very differently to run
Running Cost Formula: How Is It Calculated?
The core formula converts power (watts) and time (hours) into energy (kilowatt-hours), then applies your electricity rate.
Step 1 — Weekly Active Energy
Active kWh/week = (Watts × Quantity × Hours/Day × Days/Week) ÷ 1,000
This is the energy consumed while the equipment is actively running.
Step 2 — Weekly Standby Energy (Optional)
Standby Hours/Week = (24 × 7) − (Hours/Day × Days/Week)
Standby kWh/week = (Standby Watts × Quantity × Standby Hours/Week) ÷ 1,000
For equipment left plugged in, this adds the phantom-load energy consumed during all the hours it's not actively running.
Step 3 — Cost by Period
Weekly Cost = (Active kWh + Standby kWh) × Rate per kWh
Daily = Weekly ÷ 7, Monthly = Daily × 30.4375, Yearly = Daily × 365.25
Every equipment row's cost is summed together, and an optional monthly service charge is added on top to estimate a full bill.
Worked Example
This example walks through your current inputs above, using the same steps as the Formula section.
Input Values Used
| Input | Value | Why it is used |
|---|---|---|
| Equipment | 3 items | Sets total energy consumption |
| Rate | ₹0.1500/kWh | Converts kWh to cost |
| Service Charge | None | Adds a fixed fee to the total bill estimate |
Step 1 — Weekly Energy per Equipment
Each row's active-hours energy is (Watts × Quantity × Hours/Day × Days/Week) ÷ 1,000. Any standby watts add energy for the remaining hours in the week (168 total).
| Equipment | Active Calculation | Standby Calculation | Weekly kWh |
|---|---|---|---|
| Refrigerator | 150W × 1 × 24h × 7d ÷ 1000 = 25.20 kWh | — | 25.20 |
| Central A/C | 3000W × 1 × 8h × 7d ÷ 1000 = 168.00 kWh | — | 168.00 |
| LED Bulb | 10W × 5 × 5h × 7d ÷ 1000 = 1.75 kWh | — | 1.75 |
Step 2 — Total Energy by Period
Every row's weekly kWh is summed, then converted: Daily = Weekly ÷ 7, Monthly = Daily × 30.4375, Yearly = Daily × 365.25.
| Period | Calculation | Total kWh |
|---|---|---|
| Week | 25.20 + 168.00 + 1.75 | 194.95 |
| Day | 194.95 ÷ 7 | 27.85 |
| Month | 27.85 × 30.4375 | 847.68 |
| Year | 27.85 × 365.25 | 10,172.21 |
Step 3 — Cost by Period
Each period's total kWh is multiplied by your electricity rate (₹0.1500/kWh).
| Period | Calculation | Energy Cost |
|---|---|---|
| Day | 27.85 × ₹0.1500 | ₹4.18 |
| Month | 847.68 × ₹0.1500 | ₹127.15 |
| Year | 10,172.21 × ₹0.1500 | ₹1,525.83 |
Therefore, at ₹0.1500/kWh, your equipment costs approximately ₹127.15 per month (₹1,525.83 per year) to run.
Essential Checklist+−
Complete these critical checks before approving the work or proceeding to the next construction stage.
✓Load Input Accuracy+-
- Actual nameplate/rated watts used for major equipment, not guessed from a generic chart
- Hours per day and days per week realistically estimated, not assumed to run continuously
✓Rate & Billing Structure+-
- Electricity rate per kWh confirmed from an actual utility bill, not estimated or assumed
- Currency and rate units confirmed to match — rate entered as cost per kWh, not per some other unit
Full QC Checklist+−
Verification checklist for electricity running cost estimation — covering load input accuracy, rate/billing structure, cost calculation and interpretation, and efficiency/practical application. Use the Essential Checklist for critical checks before relying on the result; expand to Full QC Checklist for complete verification.
✓Load Input Accuracy+-
- Actual nameplate/rated watts used for major equipment, not guessed from a generic chart
- Hours per day and days per week realistically estimated, not assumed to run continuously
- Standby/phantom power considered for electronics left plugged in but not actively used
- Quantity field used correctly for repeated items, not double-counted as separate identical rows
- Seasonal variation considered for weather-dependent equipment, not applied as a flat year-round estimate
- All significant equipment included when the goal is a whole-house bill estimate, not just a few items
- True watts distinguished from nameplate VA (apparent power) for motor-driven or inductive equipment
✓Rate & Billing Structure+-
- Electricity rate per kWh confirmed from an actual utility bill, not estimated or assumed
- Tiered/slab rate structure acknowledged if your utility uses one, since this calculator assumes a single flat rate
- Time-of-use/peak-off-peak pricing acknowledged if applicable, since this calculator uses one rate regardless of time of day
- Monthly service/standing charge included only when estimating a full bill, excluded when comparing equipment running cost
- Currency and rate units confirmed to match — rate entered as cost per kWh, not per some other unit
- Additional bill line items (taxes, surcharges, fuel adjustment charges) accounted for separately, since this calculator only models energy cost plus one flat service charge
✓Cost Calculation & Interpretation+-
- Month/year averaging convention understood — an average 30.4375-day month, not a specific calendar month
- Cost share percentages used to correctly identify the biggest contributors to total cost
- Standby power's cumulative annual effect recognized, even though its per-hour draw looks small
- Result sanity-checked against an actual utility bill where possible
- Result used for relative comparison between equipment or scenarios, not treated as a guaranteed exact bill figure
✓Efficiency & Practical Application+-
- Result used to evaluate an appliance replacement/upgrade decision with a genuine cost comparison
- Highest-value energy-saving opportunities identified first, using the cost share breakdown
- Understood that motor-driven, cycling loads (like a refrigerator's compressor) have a variable real-world draw this estimate approximates as constant
- Local utility rebate or efficiency incentive programs checked separately, not assumed included in this estimate
- Future electricity rate changes considered for any multi-year planning or payback calculation
- This calculator not treated as a substitute for a professional home energy audit for larger decisions
Typical Appliance Wattage Reference
Typical running watts for common household equipment — always confirm against your actual equipment's nameplate where possible.
| Equipment | Typical Watts |
|---|---|
| Refrigerator | 100-200 W |
| Central A/C (3-ton) | 2,500-4,000 W |
| Window A/C (10,000 BTU) | 900-1,500 W |
| Electric Water Heater (storage) | 1,500-4,500 W |
| Washing Machine | 400-1,200 W |
| Clothes Dryer (electric) | 2,000-3,000 W |
| Dishwasher | 1,200-1,800 W |
| Microwave Oven | 600-1,200 W |
| Electric Kettle | 1,000-1,500 W |
| Toaster | 800-1,500 W |
| Space Heater | 750-1,500 W |
| Hair Dryer | 800-1,800 W |
| Vacuum Cleaner | 500-1,200 W |
| Dehumidifier | 250-700 W |
| EV Charger (Level 2, home) | 3,300-7,700 W |
| Pool Pump | 750-2,200 W |
| LED TV | 60-150 W |
| Desktop Computer | 100-300 W |
| Laptop | 30-65 W |
| Router / Modem | 5-20 W |
| Ceiling Fan | 15-75 W |
| LED Bulb | 5-15 W |
Typical Standby/Phantom Power Reference
Approximate power drawn by common electronics while switched "off" but still plugged in — use these as a starting point for the Standby Watts field.
| Device | Typical Standby Watts |
|---|---|
| Cable / Satellite Box | 15-35 W |
| Game Console (standby mode) | 1-15 W |
| Desktop Computer (sleep mode) | 2-5 W |
| LED / LCD TV | 0.5-3 W |
| Printer | 1-5 W |
| Microwave (clock/display) | 1-3 W |
| Coffee Maker (clock/warmer) | 1-3 W |
| Phone/Laptop Charger (no device attached) | 0.1-0.5 W |
Cable/satellite boxes are a notable exception — many stay close to full power even in standby to keep a fast channel-change and DVR recording ready, making them one of the largest phantom-load contributors in a typical home.
Typical Usage Pattern Reference
Reasonable starting ranges for hours/day and days/week — actual usage varies by household, so adjust to your own habits.
| Equipment | Typical Hours/Day | Typical Days/Week |
|---|---|---|
| Refrigerator | 24 (continuous) | 7 |
| Central/Window A/C (in season) | 4-10 | 7 (seasonal only) |
| Washing Machine | 0.5-1.5 per load | 2-4 |
| Dishwasher | 0.75-1.5 per load | 3-7 |
| Electric Water Heater (storage, cycling) | 1-3 equivalent hrs | 7 |
| LED TV | 2-6 | 7 |
| Desktop Computer | 4-8 | 5-7 |
| Room Lighting (per circuit) | 3-6 | 7 |
When should you use this running cost calculator?
- Estimating what a specific appliance or piece of equipment costs to run.
- Comparing the running cost of a current appliance against a more efficient replacement.
- Building a rough monthly or yearly electricity bill estimate from your major equipment.
- Identifying which equipment actually drives most of your electricity cost.
- Quantifying standby/phantom power cost from always-plugged-in electronics.
Quick Running Cost Tips
- Use actual nameplate watts and realistic usage patterns instead of relying on generic presets.
- Don't assume every appliance runs every day — use the days/week field for accuracy.
- Check the cost share breakdown to focus energy-saving efforts where they matter most.
- Include standby watts for electronics left plugged in but rarely actively used.
- Sanity-check the result against an actual utility bill for the same equipment and period.
- If you have a smart plug or plug-in energy monitor, use its measured watts and hours instead of a nameplate/preset estimate — real measured data is always more accurate.
- Run the calculator twice — once for a current appliance, once for a replacement — to see the real yearly savings before deciding whether an upgrade pays for itself.
- For seasonal equipment like A/C or space heating, calculate the in-season months separately rather than applying one usage pattern across the whole year.
- Group small always-on electronics (routers, chargers, cable boxes) on one switched power strip you can fully cut power to when away, and use this calculator to see what that's actually worth.
Common Mistakes
- Assuming every appliance runs 24/7 or every day of the week, badly overstating cost.
- Ignoring standby/phantom power for electronics left plugged in but switched off.
- Applying a flat rate when your utility actually uses tiered or time-of-use pricing, without adjusting for it.
- Comparing equipment options with the service charge included, which doesn't change based on what you're evaluating.
- Treating a single-season usage estimate (like summer A/C hours) as representative of the whole year.
- Confusing kW (a rate of power) with kWh (energy over time) — a 3kW appliance run for 1 hour uses 3 kWh, not 3 kW of "cost."
- Entering a motor-driven appliance's nameplate VA (apparent power) as if it were true watts, overstating cost for equipment with a power factor below 1.0.
- Using a device's maximum/surge rating instead of its typical running watts, which inflates the estimate for anything with a brief startup spike.
- Forgetting that quantity multiplies watts, not hours — 5 bulbs at 10W for 5 hours is 50W × 5 hours, not 10W × 25 hours (the energy total is the same, but entering it wrong elsewhere in a manual calculation is a common error this calculator's Quantity field avoids).
Limitations
- Uses a single flat electricity rate — does not model tiered/slab or time-of-use (peak/off-peak) pricing structures.
- Treats equipment load as steady during active hours — motor-driven, cycling loads (like a refrigerator) have a variable real-world draw this calculator approximates as constant.
- Does not model seasonal usage automatically — apply a season-appropriate hours/day and days/week yourself for weather-dependent equipment.
- Does not model future electricity rate changes for multi-year payback or savings projections.
- This is a planning reference estimate, not a guaranteed prediction of your actual utility bill.
Disclaimer: This calculator provides approximate results for planning and estimation purposes only. Actual requirements may vary based on site conditions, materials, workmanship, and local building regulations. Always consult a qualified engineer, architect, or construction professional before making final decisions.