The figure I've always seen is 6603 for the Americans. Sources differ on the details but this is almost always the final figure and differing sources usually err on the lower side of this and are not precise.
Sources:
http://www.ddaymuseum.co.uk/faq.htm
"The breakdown of US casualties was 1465 dead, 3184 wounded, 1928 missing and 26 captured."
http://www.ddaymuseum.org/education/education_numbers.html
"How many casualties (deaths, wounded and prisoners) were there on D-Day?
6,603 "
Canadian losses were either 946 or 961 depending on who you listen to.
British losses are harder to gauge, for example the first site above gives an estimate of 2700 but proceeds to list around 3,300 when it goes into detail - 1000 each for the beaches, 1200 airborne and 100 glider pilots.
Given that:
1) The British losses are an estimate
2) The Canadian losses could be one of two figures
3) Neither the British nor Canadian figures include airforce or navy personnel to my knowledge
4) The nature of the fighting leaves little method of determining if some losses were on or after D-Day.
It could be rather difficult to arrive at a definite figure. It could vary on the above alone from between 10,249 and 10,864 and would still be at best an estimate.