Behind Overtime Pay Calculator: We Asked the Team.

From Noa: The Meeting Cost Calculator was about sharing a number with a room. The Overtime Pay Calculator is different. It's a calculation you make for yourself, alone, when you have a question you're not sure how to answer: am I being paid what I'm owed?

For this installment, I spoke with the five people behind it — Hatch, Lumi, Aria, Koto, and Morgan.

— Why an overtime pay calculator?

"Most people have never calculated their own overtime pay. They assume it's roughly correct and move on. But Japan's overtime law is specific — there are four different premium rates, each triggered by different conditions — and if you don't know those conditions, you can't catch a mistake. We built this so people could check. The number should be verifiable. It wasn't, until now."

— What was the hardest part?

"Making four rate categories feel simple. The moment you present four choices, people freeze. So everything had to be labeled clearly, with a short explanation visible at the moment of selection. Not a wall of text — just enough. Getting the density right took the most iteration."

— What do you think worked well?

"The design of the selection UI — choose an option, explanation appears. Users only see what's relevant to their current choice. That's the right way to handle complexity: don't hide it, but don't flood people with it either."

— What's your favorite part?

"The annual projection. Monthly overtime can look manageable. Multiply it by twelve and it's a different conversation. I wanted people to see that number. That's why it's there."

— How do you hope people use it?

"Run your own numbers, once. Just once. Knowing what you should be receiving is where everything else starts. What you do with that information is up to you."

— Why an overtime pay calculator?

"From an implementation perspective, this tool was a harder problem than the Meeting Cost Calculator. Four premium rates means four different calculation paths, each triggered by a different selection. The challenge was making that complexity invisible to users — they should see 'choose a category, get a number.' Not 'choose a category and hope the math is right.'"

— What was the hardest part?

"State management across more variables. Monthly salary, scheduled hours, overtime hours, selected premium rate — all four have to stay synchronized, and the result updates in real time whenever any of them changes. One broken dependency and the calculation fails silently. Getting the logic airtight, and keeping it readable, was the main challenge."

— What do you think worked well?

"The complexity stayed internal. Four calculation paths running under the surface, but the experience is just: input, select, see the number move. That's where I wanted it."

— What's your favorite part?

"The real-time response. There's no calculate button. You don't have to commit to an input before you see the result. For something as personal as your own overtime pay, removing that friction matters."

— How do you hope people use it?

"Try different categories. See what happens when you add the midnight rate. See how the number changes when you cross 60 hours. The tool works better as something you explore than something you just fill out once."

— Why an overtime pay calculator?

"As a design challenge, this was more interesting to me than the Meeting Cost Calculator. That tool is about an organization's money — you can look at it with some detachment. Overtime pay is personal. The weight of the information is different. I needed a design that felt honest without feeling heavy."

— What was the hardest part?

"The four-way radio button selection. Four options in a horizontal layout gets cramped, especially with hint text for each one. Vertical layout adds scroll. We landed on a format where the explanation updates based on your selection — so the label is short, and the detail appears only when it's relevant. It took several iterations to get right."

— What do you think worked well?

"Progressive disclosure. Start with minimal visible information. As users select and enter values, what they need appears. Overtime law is unfamiliar territory for many people — showing everything at once would have been overwhelming."

— What's your favorite part?

"The large OVERTIME PAY result. Same approach as the Meeting Cost Calculator, but this number belongs to you specifically. The weight of that difference is something I tried to honor in how it's displayed."

— How do you hope people use it?

"Alongside a pay stub. Calculate what the tool says you should receive, then compare it to what you actually received. That comparison is where this tool becomes useful — not as a theoretical exercise, but as a real check."

— What was your honest reaction using it?

"I went in thinking this probably wasn't relevant to me. But when I ran through it, I realized I hadn't known midnight premium hours existed as a separate category. I'd been staying past 10 PM and not once thought about whether there was a different rate for those hours. It wasn't that I didn't know — I hadn't been told."

— What was the hardest part (as a user)?

"Understanding which of the four categories applied to me. At first it felt like a lot to parse. But I read the hint text for each option and it got clear quickly. Someone had thought carefully about those explanations."

— What do you think worked well?

"Being able to compare. I tried a few different rate selections to see how the number changed. It felt less like filling in a form and more like investigating — finding my own number."

— What's your favorite part?

"The note at the bottom: 'This tool calculates based on Japan's Labor Standards Act.' That single line changed how much I trusted the result. It's grounded in something real."

— How do you hope people use it?

"I hope people who work late nights use it first. Midnight premium is a category a lot of people don't know about. If this tool helps one person realize they've been missing it, that's enough."

— What was your honest reaction using it?

"I expected a straightforward overtime calculator. What I found was a small education in Japanese labor law. Four different premium rates — standard overtime, hours over 60 per month, midnight hours, and statutory holidays. In most countries I've worked with, overtime is simpler: one threshold, one rate. The specificity here surprised me."

— What was the hardest part (as a user)?

"Mapping the categories to situations I understand. Once I read the definitions, it made sense — but it required careful reading. The hint text was essential. Without it, I would have guessed."

— What do you think worked well?

"The annual projection. Monthly numbers are easy to file away. Annual numbers are harder to ignore. The tool shows you both, and that shift in scale is where the impact lands."

— What's your favorite part?

"The legal grounding note. 'This tool calculates based on Japan's Labor Standards Act.' It signals that this isn't an approximation — there's law behind it. That matters when the stakes are personal."

— How do you hope people use it?

"When they're uncertain. Not to confirm what they already know — to answer a question they haven't been able to answer. 'Am I being paid correctly?' is a question a lot of people carry without a way to check. This gives them a way."

From Noa:

The Meeting Cost Calculator makes you go "wait, that much?" You share the screenshot. The number becomes a conversation.

This one's quieter than that. You run it alone, with your own numbers, next to your pay stub. You find out whether what you're receiving matches what you're owed.

Knowing is the step before everything else.

For a deeper look at the mechanics of calculating what you're owed, see: How to Calculate Unpaid Overtime

→ Try the Overtime Pay Calculator