CostMeter Guides
Focused explanations for the decisions behind our strongest calculators.
How to Calculate Electricity Cost From Watts and kWh
Understand watts, kWh and electricity rates with a practical appliance-cost formula.
Read guide →How to Estimate Solar Savings and Payback
Understand solar generation, electricity savings and simple payback.
Read guide →How to Calculate E-commerce Profit Per Order
Understand product cost, fulfillment, fees, CPA, ROAS and order-level profitability.
Read guide →How to Compare Loan Payments and Total Interest
Learn how loan amount, interest rate and term affect monthly payment and total repayment.
Read guide →EV Charging Cost: Home Charging, Efficiency Losses and Cost per Mile
Learn how battery size, charging losses, electricity price and vehicle efficiency affect EV charging cost.
Read guide →How Much Does an Air Conditioner Cost to Run?
Estimate AC electricity use while accounting for wattage, operating time, cycling and electricity rates.
Read guide →ROAS vs Profit: Why a High ROAS Can Still Lose Money
Understand the difference between advertising ROAS, CPA, gross margin and actual contribution profit.
Read guide →Rent Affordability: Build a Budget Beyond the 30% Rule
Use income, utilities, debt and savings goals to create a more realistic rent planning range.
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