A report published in the highly respected British medical Journal The Lancet states this:
The risk of death was estimated to be 2·5-fold (95% CI 1·6–4·2) higher after the invasion when compared with the preinvasion period. Two-thirds of all violent deaths were reported in one cluster in the city of Falluja. If we exclude the Falluja data, the risk of death is 1·5-fold (1·1–2·3) higher after the invasion. We estimate that 98000 more deaths than expected (8000–194000)happened after the invasion outside of Falluja and far more if the outlier Falluja cluster is included. The major causes of death before the invasion were myocardial infarction, cerebrovascular accidents, and other chronic disorders whereas after the invasion violence was the primary cause of death. Violent deaths were widespread, reported in 15 of 33 clusters, and were mainly attributed to coalition forces. Most individuals reportedly killed by coalition forces were women and children. The risk of death from violence in the period after the invasion was 58 times higher (95% CI 8·1–419) than in the period before the war.
Violence accounted for most of the excess deaths and air strikes from coalition forces accounted for most violent deaths.
These are civilian deaths… they do not include Iraqi military. They could include insurgents but as most of the deaths reported are woman and children, that point is largely moot anyway.
You be the judge whether this, plus the 1200 American lives lost was worth the cost.
Here is the report as published in the Lancet.
Or you can download the PDF version of the Report.