# Free tools for your business

## Invoice generator  
  
Create professional contractor invoices. Add labor, parts, taxes, and discounts, then save as PDF.  
[Invoice generator](/content/tools/invoice-generator/index.html)

## Service price calculator  
  
Calculate profitable service prices for any job. Enter costs, set your margin, and quote with confidence.  
[Service price calculator](/content/tools/service-profit/index.html)

## Hourly rate calculator  
  
Find out if your hourly rate covers your true costs — and what you should actually be charging.  
[Hourly rate calculator](/content/tools/hourly-labor-cost/index.html)

## Email signature generator  
  
Build a professional email signature with your logo, contact details, and social icons. Copy it into Gmail, Outlook, or Apple Mail.  
[Email signature generator](/content/tools/email-signature/index.html)

## HVAC upgrade ROI calculator  
  
Show customers how fast a new system pays for itself. Get payback period, annual savings, and lifetime ROI.  
[HVAC upgrade ROI calculator](/content/tools/hvac-roi/index.html)

## HVAC rebate finder  
  
Find every rebate you can stack on a job — federal, state, utility, and manufacturer — and share a summary with your customer.  
[HVAC rebate finder](/content/tools/hvac-rebates/index.html)

## HVAC license requirements  
  
Look up HVAC license requirements for any US state. Find license types, exams, experience, and fees.  
[HVAC license requirements](/content/tools/hvac-license/index.html)

## HVAC load calculator  
  
Estimate the BTU capacity any property needs. Enter square footage, climate, and insulation to size the system.  
[HVAC load calculator](/content/tools/hvac-load/index.html)

## Air flow calculator  
  
Determine proper ventilation for any room. Enter dimensions, pick the room type, and get the CFM you need.  
[Air flow calculator](/content/tools/air-flow/index.html)

## Duct size calculator  
  
Find the right duct dimensions for any run. Pick metal or flex, enter the CFM, and get a size to order.  
[Duct size calculator](/content/tools/duct-size/index.html)

## Pipe expansion calculator  
  
Calculate how much pipes expand or contract with temperature changes. Works for copper, steel, PVC, and more.  
[Pipe expansion calculator](/content/tools/pipe-thermal-expansion/index.html)

## Pipe volume calculator  
  
Find out how much water a pipe holds based on material, size, and length. Supports copper, PVC, PEX, and steel.  
[Pipe volume calculator](/content/tools/pipe-volume/index.html)

## Electrical load calculator  
  
Calculate residential electrical load per NEC 220.83. Check if a home's panel can handle the demand.  
[Electrical load calculator](/content/tools/electrical-load/index.html)

## Voltage drop calculator  
  
Check voltage drop for any wire size or find the minimum AWG per NEC. Single-phase and three-phase.  
[Voltage drop calculator](/content/tools/voltage-drop/index.html)