Sizewise Rate Counter

What it is for

"50 million euros a year" or "300,000 km per second" become far easier to grasp when you see them per second, per day or as a counter ticking up while you read. The Rate Counter converts one rate into every common unit of time, projects it over spans from a minute to ten years and tells you when it reaches a target.

It also writes a small, self-contained HTML counter — "Light travels since you opened this page: …" — that you can paste into a blog post or a slide. The counter needs no library, sends nothing anywhere and slows down for visitors who prefer reduced motion.

Rates are constant: the tool does not model growth, seasons or daily patterns.

Worked example

The first example uses the speed of light: Amount 299,792.458, Per second, Unit km, an elapsed time of 60 s and a target of 384,400 km, the mean distance to the Moon. The summary reads: Light travels: 299 792 km per second, 17 987 500 km after 60 s. Reaching 384 400 km takes 1.28 seconds.

The table gives 1,079,252,800 km per hour, 25,902,068,000 km per day and 9,460,730,500,000 km per year — one light year.

For a budget, enter Budget spent, 50,000,000 per year in EUR with two decimals. That is 1.5844 EUR per second, 136,892.54 EUR per day and 4,166,666.7 EUR per month.

A slow rate works too: 750 litres of rain per year on a roof is 2.05 litres a day, and reaching a 10,000-litre tank takes 13.3 years.

How to read the result

• The same rate per unit of time converts the rate exactly. A month is one twelfth of a Julian year (365.25 days), so 50 million per year is exactly 4,166,666.7 per month.
• After a span of time multiplies the rate by 1 minute, 1 hour, 1 day, 1 week, 30 days, 1 year and 10 years.
• The Target callout appears when you set a target above zero.
• Live counter to embed is the HTML snippet. It starts at zero when the page opens.

Tips and common mistakes

• Pick the period the source uses (per year, per day) instead of converting it yourself first; the tool avoids rounding twice.
• Use Decimals in the counter for slow rates, otherwise the counter shows 0 for a long time.
• The unit is free text: km, EUR, litres, tweets, babies born.
• The embed uses inline styles and an inline script. On sites with a strict Content Security Policy, move the script into your own file.
• Presets in the Sizewise app cover light, the Earth's orbit (29.78 km/s, NASA) and the turning equator.

FAQ

How long is a month here?

One twelfth of a Julian year: 30.4375 days.

Does the counter keep running after a reload?

It restarts from zero, because it counts from the moment the page opened.

Can the counter count down?

No. It counts up at a constant rate; use the target line to state when a goal is reached.

Is the embed accessible?

The number is not announced on every tick (aria-live off), and it updates once per second for people who prefer reduced motion.