Accrue

Accrue is a compound interest calculator for a strategy quoted per trading day.

You enter the gain you are aiming for each market day. Accrue compounds it over the 252 days a year the market is open, then says what that comes to in the terms everyone else uses: APR, APY, and the same rate read on a calendar basis.

It is one screen. Every input is a field you edit with the chart in view, and the answer moves as you type.

What it does

• The daily rate is the input, not an annual figure divided down
• 252 market days or 365 calendar days, switchable — and it shows what your rate is on the other one
• Contributions daily, weekly or monthly
• Term in days, months or years
• The chart’s time scale is an input too: read the same projection in days, weeks, months, quarters or years
• Drag along the curve to read any point out
• A breakdown table that unfolds underneath, at whatever scale you chose
• Opens on whatever you left in it
• Light and dark, or follow your iPhone

Why the day count matters

A gain earned per trading day compounds about 252 times a year, not 365. At 0.300% a day that is 112.73% APY on a market basis against 198.43% on a calendar one — the same number, read two ways. The difference only means anything because the daily rate is what you typed, rather than an annual figure divided down.

Not a forecast

Accrue projects one scenario: the rate you enter, held every single day. No strategy does that, and the app makes no claim that any rate is achievable. It is a tool for seeing what compounding does, not advice about what to expect.