Hi Mario For such cases I use ~subseq~ to take the running window out of the complete range ~@I$2..@II$2~:
| date | measure | running avg | |-------+---------+-------------| | 01-27 | 604 | | | 01-28 | 314 | | | 01-29 | 636 | | | 01-30 | 305 | | | 01-31 | 760 | | | 02-01 | 531 | | | 02-02 | 331 | 497.29 | | 02-03 | 77 | 422.00 | | 02-04 | 621 | 465.86 | | 02-05 | 406 | 433.00 | | 02-06 | 621 | 478.14 | | 02-07 | 975 | 508.86 | | 02-08 | 252 | 469.00 | | 02-09 | 794 | 535.14 | | 02-10 | 36 | 529.29 | #+TBLFM: $3 = '(let ((len 7)) (if (> @# len) (format "%.2f" (/ (apply #'+ (subseq '(@I$2..@II$2) (- @# 1 len) (- @# 1))) (float len))) "")); N Michael