Guides
Quick answers to the questions that come up mid-project, each with the calculator built in so you can check your own numbers.
Heating and winter
- How much firewood do I need for winter?How many cords of firewood a winter takes, from occasional fires to heating the whole house, plus how to measure the wood you already have.
- What size generator do I need?How many running and starting watts you need to keep a fridge, furnace, sump pump or well pump going in a power outage, with typical appliance wattages.
- How much does it cost to run a space heater?What a 1,500 watt space heater costs to run per hour, per day and per month at typical US electricity rates, and how to cut the cost.
- What size furnace do I need?Furnace sizes in BTU for 1,500, 2,000 and 2,500 square foot homes in every US climate zone, and why the input rating isn’t the heat you get.
- What size heat pump do I need?Heat pump sizes in tons for 1,000 to 2,500 square foot homes in mild, moderate and cold climates, and what to check before you buy.
- How many bags of pellets do I need for the winter?How many 40 lb bags and tons of wood pellets a pellet stove burns in a winter, by setting and hours a day, and how long a bag lasts.
- How many Christmas lights do I need for my tree?How many lights a Christmas tree needs for a light, classic or full look, from 4 to 9 feet, and what they cost to run.
- How much does snow on a roof weigh?How much fresh snow, packed snow and ice weigh per square foot and in total on a typical roof, with the warning signs of an overloaded roof.
- What gauge extension cord do I need?The right extension cord gauge for tools, heaters and holiday lights at 25, 50 and 100 feet, and why a thin cord on a long run is a problem.
Around the house and yard
- How many bags of concrete do I need?How many 80, 60 or 40 lb bags of concrete a slab takes, with a table for common patio and pad sizes and when to order ready-mix instead.
- How much mulch do I need?How much mulch you need in cubic yards or bags, how far a yard goes at each depth, and how deep to spread it.
- How much paint do I need for a room?How many gallons of paint a room needs for two coats, with a table for common room sizes and when to buy extra.