To calculate the property tax, the authority will multiply the assessed value of the property by the mill rate and then divide by 1,000. Local Governments are also watching their costs increase as fuel costs have been taking a larger and larger chunk out of their budgets. If your property card checks out correctly, check on your home's market value. Assessed values are based on a percentage of market value which may be listed on your assessment or supplied by your tax assessor's office. A few creative property owners have suggested that they should be able to deduct their customary and standard monthly rent if the property is empty.