Watt & Wall guides
Practical home energy, renovation and decor guides
Choose a focused guide for an energy-cost question, renovation measurement, furniture decision, rug, or curtain project. Each guide states its assumptions and links to its sources.
Guide library
Choose a topic area
Start with the decision you need to make. The category descriptions explain which group is most likely to contain the answer.
Energy
Understand energy use and running costs
Choose a guide for the bill, appliance, label, or usage question you are trying to answer. Each one separates measured values from planning assumptions.
- Energy guide
Space heater monthly cost
Calculate monthly space-heater cost from rated watts, active days, daily runtime, duty cycle, and your local electricity rate.
Read guide - Energy guide
Dehumidifier IEF and cost
Relate the IEF label to water removal, then use measured energy, runtime, and your local rate for a practical cost estimate.
Read guide - Energy guide
Electric water heater use
Separate element rating from actual runtime and standby heat loss before estimating water-heating electricity use and cost.
Read guide - Energy guide
Window AC running cost
Estimate a window air conditioner's cost from rated input, compressor cycling, schedule, and your local electricity price.
Read guide - Energy guide
Standby device cost
Measure an always-on device in watts and turn that continuous load into monthly and annual electricity cost.
Read guide - Energy guide
Fridge cost versus EnergyGuide
Compare a multi-day refrigerator energy observation with the model's annual EnergyGuide kWh on the same time and price basis.
Read guide - Energy guide
Electricity costs
Find a usable electricity rate on your bill and account for fixed, tiered, or time-of-use charges before estimating cost.
Read guide - Energy guide
Appliance energy use
Choose between label watts, a plug-in meter, and annual energy labels without applying appliance duty cycle twice.
Read guide - Energy guide
Home energy audit
Use a room-by-room checklist to identify energy questions and decide when a professional home assessment may help.
Read guide - Energy guide
EnergyGuide labels
Read estimated annual use and cost on the yellow label, then compare similar models under the label's assumptions.
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Renovation
Measure paint, flooring, and tile projects
Start with the surface you need to cover, then account for openings, product coverage, cutting waste, and whole-package rounding where they apply.
- Renovation guide
Tile waste and spare boxes
Calculate base area, cutting waste, box rounding, and separately planned spare stock before ordering tile.
Read guide - Renovation guide
Vaulted ceiling paint
Measure sloped ceiling surfaces and triangular gable walls before applying coats, product coverage, and a waste allowance.
Read guide - Renovation guide
Paint and flooring
Follow a room-by-room measurement checklist for openings, product coverage, material waste, and manufacturer instructions.
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Furniture & Decor
Plan rooms, rugs, and curtains
Use the guide that matches your next decision, from checking a delivery path to sizing a rug or turning window measurements into curtain quantities.
- Furniture & Decor guide
Room and furniture measuring
Map room dimensions, obstacles, and the full delivery path before comparing them with the furniture you plan to order.
Read guide - Furniture & Decor guide
Choosing a rug size
Choose rug coverage from the furniture arrangement, then verify clear floor borders and fit inside the room.
Read guide - Furniture & Decor guide
Measuring curtains
Plan rod width, fullness, finished drop, and whole ready-made panel quantities from your window measurements.
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Put the guide into practice
Ready to work with your numbers?
Use a focused calculator and review every assumption behind the result.
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