Why use the IRS mileage rate instead of just gas?

Gas is only part of the cost of driving. The IRS standard mileage rate, around 70 cents per mile, also captures maintenance, tires, insurance, and depreciation. Using it gives the true cost per mile rather than a misleadingly low fuel-only figure.

How much is a San Diego transit pass?

A regional MTS adult monthly pass is about $72, giving unlimited rides on bus and trolley. This calculator uses that figure as the transit baseline; reduced fares for seniors, youth, and disabled riders are lower.

Does it count round trips?

Yes. You enter the one-way distance, and the tool doubles it for the round trip before multiplying by your commuting days per month, so the mileage reflects getting to work and back.

Why is parking included only for driving?

Parking near downtown San Diego employers commonly runs $150 a month or more and applies only when you drive. Transit riders avoid it entirely, which is often the deciding factor in the comparison.

Is the mileage cost tax-deductible?

Ordinary commuting between home and work is generally not tax-deductible. The IRS rate is used here purely as an accurate cost-per-mile estimate, not as a claim of deductibility for your daily commute.

San Diego Commute Cost Calculator

Commuting in San Diego costs more than the gas you pump. This calculator compares the all-in cost of driving — using the IRS mileage rate plus parking — against a $72 MTS monthly transit pass, so you can see which mode is cheaper and how much you would save by switching.

How it works

Driving cost uses the IRS standard mileage rate, which bundles fuel, maintenance, and depreciation:

monthly_miles  = one_way_miles * 2 * commute_days
driving_cost   = monthly_miles * irs_rate_per_mile + monthly_parking
transit_cost   = mts_monthly_pass (default $72)

The IRS rate (about $0.70/mile) is far more honest than a fuel-only estimate because a car wears out and loses value as you drive it. Parking is added only on the driving side, since transit riders do not pay it.

Tips and notes

If your employer subsidises parking or transit, subtract that from the relevant side. Carpooling roughly halves the per-person driving cost. For short commutes the IRS-rate driving cost can dip below the flat transit pass, while for long freeway commutes transit usually wins decisively once parking is counted.