Phone Plan Comparison Calculator

About the Phone Plan Comparison Calculator

Mobile phone deals are designed to be hard to compare. A contract with a new phone "included" hides the phone's price in a higher monthly bill. A SIM-only plan is cheap every month, but you have to buy the phone yourself. Some deals have an upfront fee, some have none; some offer unlimited data, others a fixed allowance. Looking only at the monthly price, or only at the upfront price, is the easiest way to pay more than you need.

This phone plan comparison calculator puts two plans on the same footing. Enter each plan's monthly price, any upfront cost — the phone, if you are buying it, or an activation fee — and its data allowance, and choose the number of months to compare. It gives the total cost of each plan, which one is cheaper and by how much, the effective monthly cost, the price per GB of data, and when the plan with the higher upfront cost breaks even.

How to Use the Phone Plan Comparison Calculator

Enter the months to compare — usually the contract length, such as 24.

For plan A, enter the monthly price, the upfront cost and the data allowance in GB a month.

Enter the same for plan B.

For a SIM-only plan with a phone bought outright, enter the phone's price as the upfront cost. For a contract that includes the phone, enter any upfront fee, or zero.

How the Plans Are Compared

  total cost       =  upfront cost + monthly price × months
  effective cost   =  total cost ÷ months
  price per GB     =  monthly price ÷ data allowance
  break-even       =  extra upfront cost ÷ monthly saving

Step-by-Step Example

Plan A: a contract with the phone included, 65 a month, nothing upfront, 50 GB. Plan B: the same phone bought for 800 and a SIM-only plan at 20 a month, 30 GB. Compared over 24 months.

  Plan A:       0 + 65 × 24            =  1,560.00  (65.00 a month)
  Plan B:       800 + 20 × 24          =  1,280.00  (53.33 a month)
  Saving:       1,560 − 1,280          =  280.00 with plan B
  Per GB:       65 ÷ 50 = 1.30;  20 ÷ 30 = 0.67
  Break-even:   800 ÷ (65 − 20)        =  17.8 months

After about 18 months, the lower monthly price of plan B has repaid the phone, and every month after that is pure saving.

Contracts Versus SIM-Only

A contract spreads the cost of a phone over two or three years, which makes an expensive handset affordable without a large upfront payment. But the total is often more than buying the phone outright plus a SIM-only plan, because the contract includes interest-like margins, and the monthly price does not fall when the phone is paid off. Buying outright and choosing SIM-only gives flexibility: you can switch networks any month, keep the phone as long as you like, and take advantage of new deals.

Some networks now split the bill into a device plan and an airtime plan, which makes the phone's cost clear and lets you change the airtime plan independently. These are easy to enter here: put the total device payments as the upfront cost, or add them to the monthly price.

When the Contract Ends

One of the most expensive mistakes in mobile is staying on a contract after the minimum term. Many providers continue to charge the same monthly price even though the phone has been fully paid for. Set a reminder for the end date, and switch to a SIM-only plan or negotiate a better deal. In some countries, providers must now tell you when your contract is ending and what the best price is.

Resale and Trade-In Value

Phones keep some of their value. A phone bought outright can be sold or traded in when you upgrade, reducing its true cost. Some contracts require you to return the phone at the end, or offer an upgrade only if you trade the old one in. If you expect to sell the phone, subtract its likely resale value from the upfront cost to compare fairly.

How Much Data Do You Need?

Check your phone's data usage settings for the last few months. Most people use far less than they think, because phones connect to Wi-Fi at home and at work. Streaming video on mobile data uses the most; browsing, messaging and music use much less. Choose a plan with a margin above your usual use, but do not pay for unlimited data you never need. Price per GB helps compare plans with different allowances.

Family and Multi-Line Plans

Many networks discount additional lines on the same account, so a family of three or four can pay much less per line than individuals. Compare the whole family's total cost under each option, not just the price of one line.

Understanding Your Result

Cheaper plan shows which plan costs less over the period and by how much.

Total cost gives each plan's total over the months compared.

Effective monthly cost spreads the upfront cost across the months.

Price per GB shows the value of each plan's data.

Break-even shows when a higher upfront cost pays for itself.

Worth knowing explains what happens when a contract ends.

When Should You Use This Calculator?

Choosing between a contract and SIM-only.

Upgrading your phone.

Comparing two networks' deals.

Deciding whether to keep a phone after the contract.

Choosing a plan for a family member.

Common Mistakes

Comparing monthly prices only.

Forgetting upfront fees and the phone's price.

Staying on a contract after it ends.

Paying for far more data than you use.

Ignoring resale value.