# Something increases threefold means it's up 300%, or 200%? **URL:** \ **Category:** Factual Questions\ **Created:** [November 2, 2009, 7:38am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029 "2009-11-02T07:38:27Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Koxinga](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@Koxinga](https://boards.straightdope.com/u/Koxinga)\ **Post date:** [November 2, 2009, 7:38am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/1 "2009-11-02T07:38:27Z")
I’m a tad uncertain on this. I’ve always thought that when (say) $100 increases threefold, that’s equivalent to saying it increased to 3 x $100 = $300, which in percent terms would be +200%. But I’ve seen some people (non-native English speakers, FWIW) using a shorthand of “threefold” = “300%”, which of course would yield a dollar figure of $400, not $300. Which is correct? (Or is my math screwed up either way?) ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [November 2, 2009, 7:55am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/2 "2009-11-02T07:55:47Z")
Threefold means “multiply by three” in my experience, so that would match your first example. ---
**Author:** ![ColdPhoenix](https://avatars.discourse-cdn.com/v4/letter/c/6bbea6/32.png) [@ColdPhoenix](https://boards.straightdope.com/u/ColdPhoenix)\ **Post date:** [November 2, 2009, 8:34am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/3 "2009-11-02T08:34:58Z")
$100 increased threefold is $300. $300 is 300% of $100. $300 is a 200% increase from $100. ---
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [November 2, 2009, 8:52am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/4 "2009-11-02T08:52:31Z")
I hate percents. How could a 50% difference be the same as a 33%? 200% same as 66%. It’s infuriating. And then there’s 300% **of** vs 200% _more_. ---
**Author:** ![blueninja](https://avatars.discourse-cdn.com/v4/letter/b/ad7895/32.png) [@blueninja](https://boards.straightdope.com/u/blueninja)\ **Post date:** [November 2, 2009, 10:08am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/5 "2009-11-02T10:08:41Z")
I’d say the difference is if you say it “increased by x%” or “increased to x%”. If you say it increased by 200% you’d get threefold. If you say it increased to 300% (of its original value) you get threefold. That’s my crazy non-native English speaker rationale. ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [November 2, 2009, 11:13am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/6 "2009-11-02T11:13:52Z")
Is a onefold increase the same as a twofold increase? ---
**Author:** ![ColdPhoenix](https://avatars.discourse-cdn.com/v4/letter/c/6bbea6/32.png) [@ColdPhoenix](https://boards.straightdope.com/u/ColdPhoenix)\ **Post date:** [November 2, 2009, 11:21am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/7 "2009-11-02T11:21:38Z")
> [@Reply](#): > > Is a onefold increase the same as a twofold increase? No. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [November 2, 2009, 11:57am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/8 "2009-11-02T11:57:20Z")
> [@Alex\_Dubinsky](#): > > I hate percents. How could a 50% difference be the same as a 33%? 200% same as 66%. It’s infuriating. And then there’s 300% **of** vs 200% _more_. What’s really fun is when you’re dealing with something already expressed in percent. _The nominal efficiency is 42 percent, but we’ve increased it by 4 percent_. Ummmm, what does that mean? ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [November 2, 2009, 11:58am UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/9 "2009-11-02T11:58:55Z")
> [@ColdPhoenix](#): > > No. Care to elaborate? ---
**Author:** ![Mindfield](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mindfield/32/19759_2.png) [@Mindfield](https://boards.straightdope.com/u/Mindfield)\ **Post date:** [November 2, 2009, 12:19pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/10 "2009-11-02T12:19:41Z")
Think of “\_\_\_fold” as the same as saying “multiplied by \_\_\_” where \_\_\_ is the number used in the “fold” word. Onefold = multiplied by 1 Twofold = multiplied by 2 And so on. Where percentages are concerned, it’s like this: “x% of” works the same way, so 100% of $100 is $100. If you’re adding it to something – say, “give him an additional 100% of $100” then obviously you’re giving “him” $200. If something is “up” 100% then it has doubled in value – it is “up” by an amount equalling its own value, just as “up 50%” means that something has increased by half its value, or $50 in these examples. If you have $300 where you started with $100, then you now have 200% more than you started with, because increasing $100 by 200% is $300. If something is running at 42% efficiency then increasing it by 4% means it’s now running at 46% efficiency. ---
**Author:** ![Mogle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mogle/32/12021_2.png) [@Mogle](https://boards.straightdope.com/u/Mogle)\ **Post date:** [November 2, 2009, 12:24pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/11 "2009-11-02T12:24:57Z")
> [@Mindfield](#): > > If something is running at 42% efficiency then increasing it by 4% means it’s now running at 46% efficiency. But 46/42 = 1.095, so that would be a 9.5% increase. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [November 2, 2009, 12:55pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/12 "2009-11-02T12:55:51Z")
> [@ZenBeam](#): > > What’s really fun is when you’re dealing with something already expressed in percent. _The nominal efficiency is 42 percent, but we’ve increased it by 4 percent_. Ummmm, what does that mean? Strictly speaking, it means your new efficiency is 42% \* 104% = 43.68%. If your efficiency goes from 42 percent to 46 percent, then you have increased the efficiency by 4 _points_. ---
**Author:** ![pancakes3](https://avatars.discourse-cdn.com/v4/letter/p/ba9def/32.png) [@pancakes3](https://boards.straightdope.com/u/pancakes3)\ **Post date:** [November 2, 2009, 1:03pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/13 "2009-11-02T13:03:14Z")
twofold = doubled, tripled = threefold. onefold = singled, which doesn’t mean much at all. ---
**Author:** ![DaveBfd](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DaveBfd](https://boards.straightdope.com/u/DaveBfd)\ **Post date:** [November 2, 2009, 1:15pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/14 "2009-11-02T13:15:46Z")
> [@Joe Frickin Friday](#): > > Strictly speaking, it means your new efficiency is 42% \* 104% = 43.68%. > > If your efficiency goes from 42 percent to 46 percent, then you have increased the efficiency by 4 _points_. I see it as (and Im sure EVERYONE else does) taking 42 and increasing it by 4. If there is a situation where you would need to know what an exact 4% increase of a number is, you had better damn well know you need that exact number. ---
**Author:** ![Ronald\_C.Semone](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@Ronald\_C.Semone](https://boards.straightdope.com/u/Ronald_C.Semone)\ **Post date:** [November 2, 2009, 1:35pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/15 "2009-11-02T13:35:12Z")
If I start in Reno with $1000 and I finish with $2000, I say “I doubled my money.” I increased it by 100% ( 1 times the original amount ) so that I now have 200% of what I started with. If I start in Reno with $1000 and I finish with $3000, I say “I tripled my money.” I increased it by 200% (2 times the original amount) so that I now have 300% of what I started with. If I start in Reno with $1000 and finish with nothing, I am in the real world. ---
**Author:** ![ColdPhoenix](https://avatars.discourse-cdn.com/v4/letter/c/6bbea6/32.png) [@ColdPhoenix](https://boards.straightdope.com/u/ColdPhoenix)\ **Post date:** [November 2, 2009, 1:35pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/16 "2009-11-02T13:35:39Z")
> [@Joe Frickin Friday](#): > > Strictly speaking, it means your new efficiency is 42% \* 104% = 43.68%. > > If your efficiency goes from 42 percent to 46 percent, then you have increased the efficiency by 4 _points_. Depends on the way it’s phrased. Saying “efficiency has increased by 4%” would mean 42% to 46%. Saying “output has increased by 4%” would mean 42% to 43.7%. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [November 2, 2009, 1:57pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/17 "2009-11-02T13:57:03Z")
> [@Reply](#): > > Is a onefold increase the same as a twofold increase? No, its 50 percent 🙂 ---
**Author:** ![Serenata67](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/serenata67/32/10646_2.png) [@Serenata67](https://boards.straightdope.com/u/Serenata67)\ **Post date:** [November 2, 2009, 2:15pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/18 "2009-11-02T14:15:29Z")
> [@Ronald\_C.Semone](#): > > If I start in Reno with $1000 and I finish with $2000, I say “I doubled my money.” I increased it by 100% ( 1 times the original amount ) so that I now have 200% of what I started with. > > If I start in Reno with $1000 and I finish with $3000, I say “I tripled my money.” I increased it by 200% (2 times the original amount) so that I now have 300% of what I started with. > > If I start in Reno with $1000 and finish with nothing, I am in the real world. So true. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [November 2, 2009, 2:19pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/19 "2009-11-02T14:19:33Z")
> [@ColdPhoenix](#): > > Depends on the way it’s phrased. > > Saying “efficiency has increased by 4%” would mean 42% to 46%. > > Saying “output has increased by 4%” would mean 42% to 43.7%. Why are you treating these two parameters (efficiency and output) differently when used in the same expression? “X has increased by 4%” means that the new value of X is 104% of the old value of X, regardless of what you substitute for X. Note that in this particular case, the mathematical relationship between output and efficiency does not alter things, either: if you increase output by 4%, you are increasing the numerator in the efficiency calculation by 4%, ergo your efficiency will also increase by 4%. ---
**Author:** ![Mogle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mogle/32/12021_2.png) [@Mogle](https://boards.straightdope.com/u/Mogle)\ **Post date:** [November 2, 2009, 2:20pm UTC](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029/20 "2009-11-02T14:20:31Z")
> [@ColdPhoenix](#): > > Depends on the way it’s phrased. > > Saying “efficiency has increased by 4%” would mean 42% to 46%. > > Saying “output has increased by 4%” would mean 42% to 43.7%. An increase in output doesn’t neccessarily mean an increase in efficiency, eg stepping harder on the gas pedal will increase an engine’s output but not its efficiency. [Next page](https://boards.straightdope.com/t/something-increases-threefold-means-its-up-300-or-200/516029.md?page=2)