We are the MonoTape team. “Five percent back” and “earn 2x points” are everywhere, but they all dodge the one question you care about: what does this thing actually cost me after the reward? The sticker price is honest; the effective price takes a little arithmetic, and at the shelf you rarely bother. The issue is not that the math is hard. It is that a plain calculator makes you redo it every time the rate or price changes. In this article we show how to get the effective price in one tap and keep it.
Why “percent back” doesn’t tell you the real price
A reward is a discount you have to compute. Effective price is just price minus price times the reward rate — but on a calculator that is two or three keystrokes you toss out the moment you are done. Compare two offers (3% back here, 5% back there) and you are juggling numbers you can no longer see. The reward looks like a single tempting figure, while the thing you should be comparing — the price you really pay — stays hidden.
A notes app remembers the percentages but will not do the multiplication, and a calculator does the multiplication but remembers nothing. What helps is something that computes the effective price and keeps the price and rate named beside it, so you can compare and adjust without starting over.
Label price and rate, read the effective price
In MonoTape you put the price and the reward rate on their own labeled lines and let the tape compute what you actually pay.
Now the comparison is real. A $48 item at 5% back costs you $45.60; a $46 item at 2% back costs $45.08 — the “smaller” reward wins. Because price and rate are named lines, you are comparing the prices you actually pay, not the marketing. That is the number that should drive the decision.
Change the rate, the price recalculates
Reward rates are a moving target — a campaign bumps it to 10%, a card gives a different rate, you want to check 3% versus 7%. On a calculator each what-if is a fresh calculation. In MonoTape you edit the rate line and the effective price updates on its own. Set up the structure once and test every offer just by changing one number.
One honest note: MonoTape is a calculator memo, not a rewards tracker. It does not connect to your loyalty accounts or tally your points balance. It simply lets you work out and keep the effective price, with the price and rate visible so the math is always checkable.
Seeing the real price is a clarity problem, not a math problem. Label price and rate, let the tape show the effective price, and edit the rate to compare offers. The reward stops being a slogan and becomes a number you can actually weigh.
MonoTape
A calculator notepad where you label your math and one edit recalculates everything. Effective prices, estimates, split bills — whatever you calculate stays on the tape. Free to use.
Learn more about MonoTapeFrequently asked questions
Does MonoTape track my reward points?
No. It is a calculator memo, not a rewards tracker. It does not connect to loyalty accounts or tally a points balance. It works out the effective price and keeps the price and rate visible so the math stays checkable.
How do I compare two reward offers?
Compute the effective price for each — price minus price times the rate — and compare those, not the headline percentages. A smaller reward on a lower price can still win.
What if the reward rate changes?
Edit the rate line and the effective price recalculates automatically. You can test different rates by changing one number, with no need to start over.
Is it free, and is my data private?
Yes, it is free, and everything is saved locally on your device, never uploaded. It works on both iPhone and Android.