The OB Calculator is a computer program for Windows and DOS that will calculate a pregnant woman's due date and current gestational age. The calculations are based on any one of the following: last menstrual period, conception date, known weeks gestation, or weeks gestation based on an ultrasound examination. A custom table can be printed (on one page) showing how many weeks and days she has completed on each day of her pregnancy.Every pregnant woman should know the gestational age of her pregnancy for the entire 40 weeks... in weeks and days, not in months. A sample table has been printed as a demo (see below). The OB Calculator program, which you can download, prints on paper a similar table based on your dates. Put your personalized print-out on the refrigerator door and track your progress!
If you find this program useful, please show the custom print-out to your OB caregiver. You may copy the program (OBCALC.EXE) onto a diskette and share it with your doctor or midwife. He or she can use the program to make print-outs for other pregnant women. The paper print-out is also very useful as a part of the OB caregiver's patient records.
Click here for download information on the OB Calculator.
The OB Calculator © 1995-96 was developed by York Winston, M.D. It was written primarily for health care professionals, but can be used by anyone.
Send comments/suggestions by e-mail to ywinston@erols.com.
In the example below, note that the months are listed across the top, and the days of the month are in the side margins. The due date is Jan 20. On July 5 she was 11 weeks plus 4 days, etc...
This print-out would normally fill one 8½ X 11 sheet of paper.
O B C A L C U L A T O R
for
ELLEN DEE
Read month across, day
down for (wks + days). Due Date: JANUARY 20
Day JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC Day
===============================================================================
1 37+2 41+5 ---- ---- 2+2 6+5 11+0 15+3 19+6 24+1 28+4 32+6 1
2 37+3 41+6 ---- ---- 2+3 6+6 11+1 15+4 20+0 24+2 28+5 33+0 2
3 37+4 42+0 ---- ---- 2+4 7+0 11+2 15+5 20+1 24+3 28+6 33+1 3
4 37+5 42+1 ---- ---- 2+5 7+1 11+3 15+6 20+2 24+4 29+0 33+2 4
5 37+6 42+2 ---- ---- 2+6 7+2 11+4 16+0 20+3 24+5 29+1 33+3 5
------------------------------------------------------------------------------
6 38+0 42+3 ---- ---- 3+0 7+3 11+5 16+1 20+4 24+6 29+2 33+4 6
7 38+1 42+4 ---- ---- 3+1 7+4 11+6 16+2 20+5 25+0 29+3 33+5 7
8 38+2 42+5 ---- ---- 3+2 7+5 12+0 16+3 20+6 25+1 29+4 33+6 8
9 38+3 42+6 ---- ---- 3+3 7+6 12+1 16+4 21+0 25+2 29+5 34+0 9
10 38+4 43+0 ---- ---- 3+4 8+0 12+2 16+5 21+1 25+3 29+6 34+1 10
------------------------------------------------------------------------------
11 38+5 ---- ---- ---- 3+5 8+1 12+3 16+6 21+2 25+4 30+0 34+2 11
12 38+6 ---- ---- ---- 3+6 8+2 12+4 17+0 21+3 25+5 30+1 34+3 12
13 39+0 ---- ---- ---- 4+0 8+3 12+5 17+1 21+4 25+6 30+2 34+4 13
14 39+1 ---- ---- ---- 4+1 8+4 12+6 17+2 21+5 26+0 30+3 34+5 14
15 39+2 ---- ---- 0+0 4+2 8+5 13+0 17+3 21+6 26+1 30+4 34+6 15
-------------------------------------------------------------------------------
16 39+3 ---- ---- 0+1 4+3 8+6 13+1 17+4 22+0 26+2 30+5 35+0 16
17 39+4 ---- ---- 0+2 4+4 9+0 13+2 17+5 22+1 26+3 30+6 35+1 17
18 39+5 ---- ---- 0+3 4+5 9+1 13+3 17+6 22+2 26+4 31+0 35+2 18
19 39+6 ---- ---- 0+4 4+6 9+2 13+4 18+0 22+3 26+5 31+1 35+3 19
20 40+0 ---- ---- 0+5 5+0 9+3 13+5 18+1 22+4 26+6 31+2 35+4 20
-------------------------------------------------------------------------------
21 40+1 ---- ---- 0+6 5+1 9+4 13+6 18+2 22+5 27+0 31+3 35+5 21
22 40+2 ---- ---- 1+0 5+2 9+5 14+0 18+3 22+6 27+1 31+4 35+6 22
23 40+3 ---- ---- 1+1 5+3 9+6 14+1 18+4 23+0 27+2 31+5 36+0 23
24 40+4 ---- ---- 1+2 5+4 10+0 14+2 18+5 23+1 27+3 31+6 36+1 24
25 40+5 ---- ---- 1+3 5+5 10+1 14+3 18+6 23+2 27+4 32+0 36+2 25
-------------------------------------------------------------------------------
26 40+6 ---- ---- 1+4 5+6 10+2 14+4 19+0 23+3 27+5 32+1 36+3 26
27 41+0 ---- ---- 1+5 6+0 10+3 14+5 19+1 23+4 27+6 32+2 36+4 27
28 41+1 ---- ---- 1+6 6+1 10+4 14+6 19+2 23+5 28+0 32+3 36+5 28
29 41+2 ---- 2+0 6+2 10+5 15+0 19+3 23+6 28+1 32+4 36+6 29
30 41+3 ---- 2+1 6+3 10+6 15+1 19+4 24+0 28+2 32+5 37+0 30
31 41+4 ---- 6+4 15+2 19+5 28+3 37+1 31
-------------------------------------------------------------------------------
Last menses = 0+0 Due Date: JANUARY 20
Conception = 2+0
Due Date = 40+0 ELLEN DEE
Based on LMP (28d)
Printed on 08/11/96