Just finished calculating pi to 30 trillion places.

[Pete]

the simplest and fast way to calculate pi is to use the Gauss–Legendre algorithm https://en.wikipedia.org/wiki/Gauss%E2%8..._algorithm
the Pi - Chudnovsky with binary splitting is much faster here's a version in FreeBasic https://www.freebasic.net/forum/viewtopi...85#p178885

all calculations need to be performed to full precision

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   digits=100
   pow2=1
    c0=0: ak = c0: bk = c0: ab = c0: asq = c0
    c1=1: a = c1: ck = c1
    c2=2: b = c2
    c05=.5: sum = c05

    b=sqr(b)
    b=c1/b
    for k=0 to fix(log(digits)*1.44269504088896)
        ak=a+b
        ak=c05*ak
        ab=a*b
        bk=sqr(ab)
        asq=ak*ak
        ck=asq-ab
        pow2=pow2*2
        tmp=ck*pow2
        sum=sum-tmp
        a = ak: b = bk
    next
    tmp=asq/sum
    pie=c2*tmp
    print pie

@Jack

I can't say I'm a fan of this one. Digits variable at 100 runs 6 iterations. I tried other iterations with less accurate or completely skewed results. So the...

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fix(log(digits)*1.44269504088896)

...is lost on me. at digits = 100 the output was: 3.141697. Is there any way to get that more accurate and produce more digits?

Pete