Am I paying for more mobile data than I use?
Work out what you actually use before deciding what to pay for, compare contracts on their total rather than their monthly price, and narrow down a signal problem without buying anything.
Check my data useFree, no account, and nothing you enter leaves your browser. Two minutes, and your phone already has the answer if you want to check ours.
What do you actually use?
Start here. Every other decision on this page depends on it, and it is the one figure nobody is told after the day they sign up.
- Data use
You have no idea how much mobile data you actually use, or how much you need.
What does it really cost?
The monthly price is an instalment, not the price. These work out the total, which is the only figure two contracts can honestly be compared on.
- Contract cost
A contract is quoted at a monthly price and you want to know what it costs in total.
- SIM-only or contract
You cannot tell whether buying a phone and taking a SIM-only plan beats a bundled contract.
When something is not working
Nothing to do with contracts. Both of these usually end somewhere free — a setting, a battery, or a SIM the network will replace for nothing.
- Signal check
Your signal is poor and you do not know whether it is you, your phone or the network.
- Repair or replace
Your phone is getting old and you do not know whether to fix it or replace it.
Going abroad
Roaming is cheap if it is chosen deliberately and expensive if it is defaulted into. The difference is one number, worked out before you leave.
- Roaming cost
You are going abroad and cannot work out what using your phone there will cost.
How mobile plans and coverage work
- How much mobile data do I need?
What a realistic month looks like at each allowance size, why the honest answer is a range, and how to find what you actually used.
- What uses the most mobile data?
The activities that dominate a monthly allowance, in order, and the two that account for most of the usage nobody can explain.
- SIM-only versus a phone contract
What a bundled contract actually bundles, why the comparison is usually made wrongly, and when bundling genuinely wins.
- How to work out the true cost of a phone contract
Upfront payments, mid-contract increases, out-of-bundle charges and cashback that has to be claimed — and how to get to one comparable number.
- Why is my mobile data slow?
Why a full signal and slow data is the normal case rather than a contradiction, and how to tell congestion from everything else.
- Why does my phone lose signal indoors?
What buildings do to mobile signal, why newer buildings are often worse, and the free setting that solves it outright.
- Is 5G worth paying more for?
Where 5G genuinely helps, where it makes no difference on a phone, and the case where it is slower than the 4G it replaced.
- How to reduce mobile data usage
The changes that actually move the number, in order of how much they save and how little you will notice them.
- Repair or replace a phone?
How to compare a repair against a replacement per year of use, and the three cheap explanations that get mistaken for an old phone.
- How roaming charges work
Passes, allowances, fair-use caps and out-of-bundle rates — what each one means and which of them decides your bill.
What these tools do not do
We do not list networks, tariffs or prices, and we do not rank them. Every figure here comes from the contract or the offer you are actually looking at.
We do not hold a table of roaming rates. They change without notice and differ by tariff, so a stale table would be worse than none — you enter the rates from your own contract.
We do not check whether your phone still gets security updates. We cannot verify your model, so we take what you tell us and point you at the manufacturer.
We do not connect to your network or your phone. Nothing is measured, and nothing you enter leaves your browser.