function calculate2018Mileage() {
var busMiles = parseFloat(document.getElementById("businessMiles").value) || 0;
var medMiles = parseFloat(document.getElementById("medicalMiles").value) || 0;
var charMiles = parseFloat(document.getElementById("charityMiles").value) || 0;
// 2018 Rates
var busRate = 0.545;
var medRate = 0.18;
var charRate = 0.14;
var busDeduct = busMiles * busRate;
var medDeduct = medMiles * medRate;
var charDeduct = charMiles * charRate;
var totalDeduct = busDeduct + medDeduct + charDeduct;
document.getElementById("resBus").innerHTML = "$" + busDeduct.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resMed").innerHTML = "$" + medDeduct.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resChar").innerHTML = "$" + charDeduct.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotal").innerHTML = "$" + totalDeduct.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resultDisplay").style.display = "block";
}
Understanding the 2018 Standard Mileage Rates
For the tax year 2018, the Internal Revenue Service (IRS) issued the optional standard mileage rates used to calculate the deductible costs of operating an automobile for business, charitable, medical, or moving purposes. These rates reflect the variable and fixed costs of operating a vehicle, including gas, oil, repairs, and depreciation.
IRS Mileage Rates for 2018
The rates for 2018 saw a slight increase from the 2017 tax year due to rising fuel and maintenance costs. The breakdown of the rates is as follows:
Purpose
Rate Per Mile
Business
54.5 cents
Medical or Moving
18 cents
Charitable Service
14 cents
Key Changes and Rules for 2018
It is important to note that the Tax Cuts and Jobs Act (TCJA), which took effect in 2018, significantly altered who can claim these deductions:
Employees: Under the TCJA, employees can no longer claim an itemized deduction for unreimbursed employee business expenses. This means if you drive for your employer and they do not reimburse you, you generally cannot deduct those miles on your federal return.
Self-Employed: Small business owners and self-employed individuals can still deduct business miles on Schedule C.
Moving Expenses: The deduction for moving expenses is now generally limited to active-duty members of the Armed Forces moving under orders.
Calculation Example
Suppose a freelance consultant drove 5,000 miles for business meetings in 2018. To calculate the deduction:
5,000 miles × $0.545 = $2,725.00
Additionally, if that same individual drove 500 miles for charitable volunteer work, they would add:
500 miles × $0.14 = $70.00
The total tax deduction for the year would be $2,795.00.
Record Keeping Requirements
To successfully claim the mileage deduction, the IRS requires taxpayers to maintain a contemporaneous log. This log should include the date of the trip, the destination, the business purpose, and the number of miles driven. Using a dedicated mileage tracking app or a written diary is essential for documentation in the event of an audit.