How this calculator works
Carriers quote a price before taxes, fees and device payments. This builds the real monthly bill and cost per line; enter an all-in per-line price from another plan to see the yearly difference. Taxes and fees vary by state and carrier, so they are an input.
- Service = (base price + price per line × lines) × (1 + taxes and fees %).
- Monthly bill = service + device payments; per line = monthly bill ÷ lines.
- Yearly saving from another plan = (service − other plan's all-in price per line × lines) × 12. Device payments are left out, because they don't change when you switch.
Worked example
With these inputs: plan base price per month $40; price per line $30; number of lines 4; taxes and fees 12%; device payments per month $0.
The result is monthly phone bill $179.20, with per line $44.80 and service only, per line $44.80.
Where the extra on a phone bill comes from
A wireless bill usually carries federal, state and local taxes, a Federal Universal Service Fund charge, 911 fees, and carrier fees such as administrative or regulatory cost recovery charges. Together they often add 10% to 20% or more to the advertised price, depending on your state and carrier. The FCC's guide to understanding your telephone bill explains the common lines.
Device payments are a separate cost. They look like part of the phone bill but they're really an installment loan for the phone, and they end when the device is paid off.
Comparing plans honestly
Compare service only, all-in: the other plan's price per line including its taxes and fees. Prepaid and smaller carriers often quote prices with taxes included, while postpaid plans rarely do. Check whether the cheaper plan drops something you use, such as hotspot data or international roaming, and whether autopay discounts require a debit card.
Once you've picked a plan, add the monthly total as a bill so you can see if it changes. Promotional credits that expire are a common reason a phone bill quietly goes up; the Bill Increase Calculator shows what a change costs over a year.
Sources
Frequently asked questions
How much does each line on my phone plan cost?
Add the base price and all per-line prices, add taxes and fees, then divide by the number of lines. In the example — $40 base, $30 per line, four lines, 12% taxes and fees — the bill is $179.20 a month, $44.80 per line, and $2,150.40 a year.
Why is my phone bill higher than the advertised price?
Advertised prices usually exclude taxes, government fees and carrier surcharges, and sometimes assume an autopay discount. Device installments and add-ons like insurance come on top.
How do I compare a cheaper plan?
Enter the other plan's all-in price per line in the "Compare a plan" field. The calculator shows the yearly saving (or extra cost) on service; device payments stay the same either way.
What percentage should I enter for taxes and fees?
Divide the taxes-and-fees total on a recent bill by the plan charges before them. It depends on your state and carrier, which is why it's an input rather than a fixed rate.
Is it cheaper to have everyone on one family plan?
Usually the price per line falls as lines are added, but check the per-line figure the calculator gives against an individual prepaid plan for each person — sometimes the family plan isn't the cheapest.