The post-tax net present value of the project, using an 8% discount rate, jumped by A$69 million, or 71.6%, to $166 million, while the internal rate of return increased by 19.3% to 36.4%.
Capital costs have dropped by around 10% to $132 million, and the payback period fell from 3.1 years to 2.5 years.
The average gold price used in the optimisation study was $1700/oz, $50/oz higher than the October feasibility study.
Three weeks ago Capricorn announced a 25% increase in ore reserves to 28 million tonnes at 1 gram per tonne gold for 892,000 ounces of gold, and a jump in resources to 45Mt at 1gpt gold for 1.4 million ounces of gold.
As a result, gold production at Bibra is forecast to increase from 660,000oz over 6.5 years to 823,000oz over 8.5 years.
All-in sustaining costs have risen slightly to $1038/oz, due to a small reduction in the life-of-mine head grade from 1.06 grams per tonne to 1gpt, a 2.2% increase in mining costs and a 0.5% fall in expected recoveries.
The final pit design allows for a four-stage open pit, up from three-stage, with a life-of-mine strip ratio of 4.8:1, with the deferral of material movement in the early years expected to increase production at lower costs.
"In parallel with the final stages of permitting the Karlawinda gold project, our team have also been working with our consultants to further enhance the value of the project - and the results have been fantastic," Capricorn executive chairman Heath Hellewell said.
"The value of the project has increased by approximately $100 million with improved rates of return and quicker payback.
"This outstanding result highlights the serious potential of our project and brings us even closer to becoming Australia's newest significant gold producer."
Capricorn has already short-listed banks ahead of locking in the financing in the September quarter.
Hellewell recently said the company was expecting to secure around $100 million in debt, with the rest in equity.
Capricorn has also launched a tender process for drill and blast, and load and haul contracts, with the results to help the company decide on a preferred mining scenario.
Based on a 56-week build, Capricorn is aiming for first gold in the September quarter of next year.
Shares in Capricorn were unchanged at A6.9c today, valuing the company at just over $51 million.