# "To increase by" v/s "To increase to"

I'm not a student with English as my mother tongue. I'm analysing an English text. I looked up in the dictionary the verb "to increase" and the noun "increase". I found these examples:

• Japan's industrial output increased by 2%
• Our cross margin increased to 24%

What is the difference between these two sentences?
Does "by" in the first sentence show that 2% is the maximum percentage of the increase?
Does "to" in the second sentence show that there has been a progress in the action?
Has the level of the increase started hypothetically, for example, from5%, then 10%, then 15% and now is 24%?

Concerning the noun 'increase' I found these examples:

• An increasing number OF customers shop online.
• Any increase in production would be helpful.

Why is the preposition "of" used in the first example and "in" in the second?

You can have an amount of something. It might be money or might be anything else. But I will use money as an example. So imagine I have £50 on Monday and on Tuesday I have £75. :)

The amount of money has increased.

It has increased to £75. That is the final amount.

It has increased by £25, that is the change in money

But £25 is 50% of £50 so I could also say

It has increased by 50%.

I could also say "It is 150% of the value on Monday"

Now suppose I have something that is measured in %, for example the unemployment rate is measured as a percentage of the population.

In January it was 10%, in February it is 24%

It has increased to 24% (The final rate is 24%)

Now in this situation using "by" often causes mathematical mistakes. You should say

It has increased by 14 percentage points.

But many people say "it has increased by 14%" even though this is mathematically confusing

In your examples the Japanese industrial output is measured in Yen. There has been an increase. The change in output is 2/100 of the previous output.

In the second example, the cross margin was less than 24%. Now it is 24%

Concerning increase. We use "a number of" which justifies the use of "of". We also use "of" with a value

We use "in" with the thing that is increasing

An increase of 700 in the number of passengers.

An increase of 30% in the size of hamburgers.

• upvoted, but it only answers the first bit of the question ;) Dec 30, 2020 at 14:17
• I think the second part could be a separate question, but I've briefly addressed it now. Dec 30, 2020 at 14:25
• "It has increased to 24% (The final rate is 25%)" ?
– fev
Dec 30, 2020 at 16:02
• fixéd.......... Dec 30, 2020 at 16:06

Japan's industrial output increased BY 2% (it gained 2%)

Our cross margin increased TO 24% (from a lower percentage which can be 23% or less, it has reached the percentage of 24% )

Then

An increasing number OF customers shop online.

(the number OF customers increased - here OF has nothing to do with increasing. "increasing" is merely used as an adjective describing "number" and means A number OF customers that is increasing.)

Any increase IN production would be helpful.

The expression is to increase in something (be it quantity or number). You use OF for percentages though. For example:

This year we witnessed a surprising increase OF 20% IN sales.

• You have made a mathematically confusing example. An increase from 46% to 48% is an increase of two percentage points, but it may not be a two percent increase, because 2% of 48% is not 2%....Lots of people get this confused. especially journalists. Dec 30, 2020 at 14:19
• @JamesK: Oops, I was never good at maths.
– fev
Dec 30, 2020 at 15:58

To identifies a target or destination. If X is 25, and then you increased X to 50, X is now 50.

By identifies something that is used, but isn't the "final product". If X is 25, and then you increased X by 50, X is now 75.

An increasing number OF customers shop online

Any increase IN production would be helpful

Of X is used because customers is countable (you would ask "how many customers" and not "how much") and each X is considered an independent individual.

In X is used because production is probably not countable (you would ask "how much production" and not "how many production") and there's no "each production".

Here are my short explanations:

• "increased by" means that before increasing it was 100\$, and after increasing it is 150\$, so you would say:

The money in the bank account increased by 50\$

• "increased to" means that before increasing it was 100\$, and after increasing it is 150\$, so you would say:

The money in the bank account increased to 150\$