Calculating time penalties

[snowy]

I'm calculating time penalties for competitors going over time.
A3 contains length of course in m
B3 contains speed in mpm
In C3(optimum time)= B3/C3/24/60 (formatted as hh:mm:ss)
Each competitor receives 0.4 penalties for each second over optimum time
When A3=2000,B3=500,C3=00:04:00

A7:A50 is their start time
B7:B50 is their finish time
C7:C50 = b7-a7, etc (formatted as hh:mm:ss)
D7:D50(time penalties) = if(c7>$C$3,(round(c7-$c$3)*84600,0))*0.4,0) (formatted as number with 1 decimal)

If A is 09:00:00 for each competitor,
B7=09:04:00, C7=00:04:00, D7= 0
B8=09:04:12, C8=00:04:12, D8=4.8
B9=09:04:24, C9=00:04:24, D9=9.6
B10=09:04:25, C10=00:04:25, D10=9.6

Obviously D10 is incorrect & should be10.00 & any further times will be incorrect.
The answer to c10-$c$3 has to be a whole no. which is why I used round. (If I don't use round D10=9.8 , which is incorrect.
In this case it is rounding 24.47916666 to 24,which is obviously mathematically correct but I want it to be 25.

Grateful for any help, thank you.

 

[Ruddles]

In C3(optimum time)= B3/C3/24/60 (formatted as hh:mm:ss)

Do you mean A3/B3?

 

[Ruddles]

= if(c7>$C$3,(round(c7-$c$3)*84600,0))*0.4,0) (formatted as number with 1 decimal)

Oops!

 

[snowy]

Yes, sorry I do mean A3/B3.

 

[Ruddles]

And you changed the 84600 to 86400? It all worked fine when I corrected that.

 

[snowy]

Thanks from a very daft excel beginner who will leave ALL the maths to excel from now on!

 

[Ruddles]

That number will be burned permanently into your memory in no time at all!