Some links on this site may earn us a commission; the cheapest route is always shown first. Disclosure
About CarrierMath
I'm Matthew Setiadi. I'm a Computational Data Science student at Temple University in Philadelphia, doing a combined bachelor's and master's. I grew up in Indonesia and moved here for school. I built this, I maintain it, and I'm the only person working on it.
I built it because I needed it myself. Every time I looked at getting a phone, the answer changed depending on how long I was willing to dig. A deal that looked free had a 36-month contract behind it. A plan that looked cheap doubled after the intro term. The savings were never in finding a secret — they were in how far I was willing to read.
Then my family needed phones. Four lines: my parents, my sister, me. My parents were about to make a decision worth thousands of dollars over three years based on what a carrier's website said, in a language that isn't their first. So I did the math myself. I built them a guide in Bahasa Indonesia comparing every carrier and every combination, and we decided from numbers instead of marketing. That guide became this calculator.
How it works
All the math happens in tested code. Every price traces to a source — usually the carrier's own FCC Broadband Facts label, the disclosure they're legally required to publish and almost nobody reads. When I don't have a verified number, the site says so instead of guessing. When a promotion hasn't been announced, you get a range, not a confident figure.
How it’s free
If you switch through a link here, I may earn a commission. Your price is exactly the same either way — the carrier pays it, not you. That's the whole business model.
What I’d ask
Go check my numbers. Open the carrier's site, find the FCC label, and see if it matches what I'm showing you. If it doesn't, tell me and I'll fix it. I'd rather be corrected than trusted.
The cheapest answer isn't always the one that pays me. Sometimes the right answer is a carrier I have no relationship with at all. It still shows up first.
Questions or corrections: hello@carriermath.com · Instagram
See the 36-month math for your own family.
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