NOTE: Our guides provide certain numbers and details but calculators can (although are not necessarily guaranteed to) be more reliable in providing numbers that are more applicable to your nation.
This calculator provides an estimate of the population you will have at certain infra levels: https://www.cybernations.lyricalz.com/tools/popcalc
Lyricalz in general is a good source of a vast array of information.
This calculator provides an estimate on infra jump costs and infra upkeep costs: http://www.intelisol.org/CNCalc/CN_SE_Infra_Calc_100.htm
This calculator provides an estimate on tech purchase costs: http://www.intelisol.org/CNCalc/CN_SE_Tech_Calc.htm
This calculator provides an estimate on battle odds. http://heisanevilgenius.com/cybernations/battle.php